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Air Bind Effect on Door Slam Durability Performance | In the vehicle development process, the door slam durability assessment is of significant importance in the estimation of fatigue life for body closure system. So far, various exertions have been taken into consideration to better represent the door slam simulation for door durability performance. Nowadays, with computer aided engineering (CAE) being extensively implemented, simulation procedures are constantly being investigated in order to get precise outcomes as physical testing. In a real world scenario, the customer closes the door frequently against the sealed cabin which offers the cabin pressure to close. The cabin pressure acts in the opposite direction of door closing providing the damping effect and minimizes the overall damage to the structure. Currently, simulations are focused on determining the total energy required for closing the door by summing up the energy lost in the weather seal and latch. Often the energy required to overcome the air-bind effect is neglected in the analysis. This work addresses the air bind effect on structural durability performance of swing door, simulating customer usage over a 10-year vehicle lifecycle with using stress analysis in explicit solver and strain-life analysis in fatigue solver. |
Prediction of Automotive Side Swing Door Closing Effort | The door closing effort is a quality issue concerning both automobile designers and customers. This paper describes an Excel based mathematical model for predicting the side door closing effort in terms of the required minimum energy or velocity, to close the door from a small open position when the check-link ceases to function. A simplified but comprehensive model is developed which includes the cabin pressure (air bind), seal compression, door weight, latch effort, and hinge friction effects. The flexibility of the door and car body is ignored. Because the model simplification introduces errors, we calibrate it using measured data. Calibration is also necessary because some input parameters are difficult to obtain directly. In this work, we provide the option to calibrate the hinge model, the latch model, the seal compression model, and the air bind model. The door weight effect is geometrically exact, and does not need calibration. The capabilities and accuracy of the developed model are demonstrated using the front and rear doors of a production vehicle. |
Mixture Distributions in Autonomous Decision-Making for Industry 4.0 | Industry 4.0 is expected to revolutionize product development and, in particular, manufacturing systems. Cyber-physical production systems and digital twins of the product and process already provide the means to predict possible future states of the final product, given the current production parameters. With the advent of further data integration coupled with the need for autonomous decision-making, methods are needed to make decisions in real time and in an environment of uncertainty in both the possible outcomes and in the stakeholders’ preferences over them. This article proposes a method of autonomous decision-making in data-intensive environments, such as a cyber-physical assembly system. Theoretical results in group decision-making and utility maximization using mixture distributions are presented. This allows us to perform calculations on expected utility accurately and efficiently through closed-form expressions, which are also provided. The practical value of the method is illustrated with a door assembly example and compared to traditional random assembly methods and results. |
A Study on Various Structural Concepts of Automotive Door Trim | An automobile door is a complex module, which consists of various fixed and movable subassemblies and components. Parameters such as safety, vehicle dynamics, aesthetic and strength are critical while designing the door assembly. Apart from the above, the design of door trim should minimize BSR (buzz squeak and rattle) at vehicle running conditions. Stiffness is one of the key engineering requirements which if not optimized will result in higher BSR levels and failure of the door trim components. In this study, more importance is given to optimize the stiffness of door trim. As per DVP (design verification and planning) standards of the OEMs, the range of deflection for the plastic trim parts is defined considering the conditions, comfort level and location of use. If stiffness is higher than the requirement, the door trim plastic parts are harder and will violate the quality and safety norms. If it is lower, then trim parts will not meet the functional requirements and safety norms. To achieve the optimized stiffness within the range, various design proposals capturing different structural concepts are constructed and analyzed. |
Internal Pressure Characteristics when Evaluating Dynamic Door Blow Out Deflection | Wind noise is one of the most influential NVH attributes that impact customer sensation of vehicle interior quietness. Among many factors that influence wind noise performance, the amount of dynamic door deflection under the pressure load due to fast movement of a vehicle plays a key roll. Excessive deflection could potentially lead to loss of sealing contact, causing aspiration leakage, which creates an effectual path through which the exterior aerodynamically induced noise propagates into the vehicle cabin. The dynamic door deflection can be predicted using CFD and CAE approaches which, in addition to modeling the structure correctly, require a correct pressure loading composed of external and internal pressure distributions. The determination of external pressure distributions can be fulfilled fairly straightforward by using commercial CFD codes such as Fluent, Star CCM+, Powerflow and others. However, the capability of predicting the internal pressure due to high wind speed outside of a vehicle has not been developed. This work looks into the internal pressure characteristics associated with the dynamic loading setup that is required for analytical efforts. The work is based on the wind tunnel measurement data involving several vehicles. By comparing the measured internal pressure data, along with CAE results, the issues are summarized and a conservative internal pressure load value is recommended. |
Structural Integrity Evaluation of Plastic Welding (Heat Stake) Tower in Door Trim Panels of Vehicles Using Finite Element Method | Structural integrity is a characteristic that must be evaluated during development of plastic parts as door trim panels. One of the critical areas in door trims is the interface between different parts that often use heat stakes due to process capacity and low costs. To predict issue on those interfaces, a methodology combining finite element analysis (FEA) and physical test results was applied to drive design in two door trim designs, with different material combinations. Aiming to support FEA conclusions, physical tests were performed to determine the maximum retention force that a heat stake withstands, indicating values about 168N for heat stakes of medium impact polypropylene blend >PP+EP(D)M-T<. and 216N for stakes of unfilled polypropylene copolymer >PP<. These values were used as upper limits for reaction forces provided by FEA in each heat stake under a load of 600 N at Pull Handle. The results for first door trim design indicated no structural issue in any heat stake, what generated a weld process investigation. Its conclusion indicated as root cause the weld quality. The results for second door trim design indicated an issue in one heat stake that required a relocation to redistribute the load. After including a new heat stake and redistributing their position, simulation indicated lower efforts, meeting the requirements. This methodology proved to be efficient to evaluate heat stakes performance during door trim development process. |
Small Overlap Impact Countermeasure-Front Door Hinge Pillar Dual Box | Since the inception of the IIHS Small Overlap Impact (SOI) test in 2012, automotive manufacturers have implemented many solutions in the vehicle body structure to achieve an IIHS “Good” rating. There are two main areas of the vehicle: forward of vehicle cockpit and immediately surrounding the vehicle cockpit, which typically work together for SOI to mitigate crash energy and prevent intrusion into the passenger zones. The structures forward of vehicle cockpit are designed to either 1) absorb vehicle energy from impact to the barrier, or 2) provide enough strength and rigidity to aid deflection of the vehicle away from the barrier. The structures which are immediately surrounding the vehicle cockpit (known as pillars and rocker/sills) are traditionally components designed to be highly rigid sheet metal panels to protect the occupant during crash events. This paper focuses on a concept for a portion of the cockpit structure that combines energy absorption and high rigidity structure, which are not typical in this area of a vehicle’s architecture. Using CAE methods, it is observed that a vehicle’s SOI structural rating will be enhanced utilizing the presented concept. |
Evaluation of Minimum Door Closing Velocity Using Analytical Approach | Door closing velocity (DCV) is one of the important design parameter for door durability performance. The closing velocity varies with the design parameters and physical properties of the door. The variation in door closing effort may increase or decrease the durability of the door and body components, this can be a concern when the overall vehicle durability performance is considered. This paper gives a mathematical model to calculate the door closing effort accounting the energy sink from various door design parameters such as door seal, latch, hinge, door weight, checkstrap and cabin-pressure. In addition to this, the MS-Excel based computation tool has been developed, which aims to calculate the door closing velocity and energy contribution from each design parameter. This tool is very interactive and effective for durability engineer and helps in improving the quality of vehicle door design. This paper also provides the result comparison study with CAE approach for design parameters as seal stiffness, latch, hinge, door weight and checkstrap. |
Innovative Door Design for Commercial Vehicles | Design of body structures for commercial vehicles differs significantly from automotive due to government, design and usage requirements. Specifically, heavy truck doors are not required to meet side impact requirements due to their height off the ground as compared to automobiles. However, heavy truck doors are subjected to higher loads, longer life, and cannot experience permanent deformation from overload events. Aluminum has been used intensively in commercial vehicle doors and cab structures for over 50 years by several different manufacturers in North America. It has been only in the last few years that aluminum has appeared in automotive door structures other than in high-end luxury vehicles. Commercial vehicle customers are expecting the same features found in premium automobiles resulting in opportunities to learn from each other's designs. In order to optimize the strength and weight of a commercial vehicle door, a new aluminum intensive structure was developed. The new structure featured a unique architecture that was the first in the industry to use a multi-cavity aluminum extrusion joined to stamped sheet reinforcements in order to provide a direct load path between the hinges and the latch. The shape of the extrusion also allows the use of a one piece glass and door mounted mirror. The “barn door” architecture of the inner structure of the door allowed for gauge optimization of the both the inner and outer stampings, the two largest and heaviest components of the assembly. Additionally, the use of an extrusion allowed for a single drop glass for improved visibility and the ability to use a door mounted mirror with only one extra reinforcement. Overall the design architecture used in the new doors provide best in class structural performance, sealing and features normally found in luxury automobiles for the first time in the heavy truck industry. |
Striker with bumper implementation to improve chucking noise issues | Investing in quality as added value to products becomes a means of guaranteeing satisfaction as well as customer loyalty, making it competitive in its respective segment. In the automotive business, this has not been different, It can observed a progress in the perception and customers demand in quality in the last few years. At the same time, that the industries need to guarantee the cost and time of response to the dissatisfaction of the customers. In this project, was possible to implement a locking door concept, with an effective solution to the door vibration problem in a B platform, vehicle model in South America. |
The Study of Optimization of Sliding Door Effect | A sliding door system is one of the vehicle door types, which is generally applied to the MPVs. The Sliding door is contains three rails (an upper, a center, and lower rail), which are mounted on body structure, and three rollers (the upper roller, the center roller, Lower roller), which are mounted on the sliding door side. The system is different from a swing door, rotated by hinge axis. To set up sliding door layout for better performance, predict operating force is one of the main factors, But The door moving trace is on three-dimension, hard to calculate and predict. So in this study, it is an object to analyze the impact between the main factors affecting the performance of the closing and open performance and the sliding door through the study formula and a layout scheme for ensuring the best operating performance of the sliding doors. |
Automatic Drilling and Fastening System for Large Aircraft Doors | Electroimpact has developed a system for drilling and fastening of cargo door structures which efficiently addresses many of the manufacturing challenges that such parts present. Challenges to door automation include 1) the presence of an inner skin that must be processed, in addition to the outer skin, and 2) a stiff frame structure, which makes the clamping and drilling processes that are typical to automated fastening machines very unforgiving of any errors in workpiece positioning. In this case, the manufacturing cell was to be installed in an existing facility with very limited ceiling height, further complicating the system and process design. New methods were devised to solve these problems, and the solutions found will likely have utility in future applications. |
In-Situ Characterization of Vibrations from a Door Mounted Loudspeaker | In the automotive industry, there is an increasing need for gaining efficiency and confidence in the prediction capability for various attributes. Often, one component or sub-system is used in a number of car models of one vehicle platform. Many of these components are potential sources of noise, vibration and squeak and rattle. In order to provide an early prognosis, vibro-acoustic source characterization in combination with the source-to-response transfer behavior are required. This paper describes the process of predicting the vibrational behavior due to a woofer, which could induce squeak and rattle, on a door panel. Blocked forces, determined indirectly in-situ by frequency response functions and operational accelerations, were used for quantifying the source activity. Those forces were in a second step loaded on to a finite element model in order to predict the response when the speaker was mounted to another position in an upcoming car model. Prior to this, comparisons between the measured and simulated response for the same car model were made, with satisfying agreement. |
Trimmed Door Audio Response Hybrid Modeling Assessment | The door response to audio excitation contributes to the overall performance of a vehicle audio system on several items: acting as a cabinet, it influences the loudspeaker response, but it also radiates unwanted sound through the inner door panel. Associated design issues are numerous, from the loudspeaker design to door structure and inner panel definition. Modeling then appears as an unavoidable tool to handle the acoustic response of the loudspeaker in its actual surrounding as well as the door inner panel radiation. In the low frequency range (<300 Hz), the loudspeaker is conveniently modelled using the classical Thiele&Small 1 D model. The interaction with the door and the acoustic surroundings requires a more detailed Finite Element modeling considering the acoustic loads on both sides of the loudspeaker membrane and the force at the loudspeaker frame interface with the door structure. The proposed hybrid modeling is first assessed by comparison of the computed and the measured membrane’s displacement. An update of the T&S parameters is performed in order to optimize the model. Then, the computed loudspeaker frame displacement and the acoustic loads may be checked against measurement. Finally, the computed vibrational response of the trimmed door is compared to an extensive 3D LASER measurement. Such an analysis allows the loudspeaker membrane displacement control as well as the inner door panel’s motion that may radiate unwanted sound. Previously proposed indicators are used to quantify the door audio performance. |
Vehicle Side Safety Enhancement through Door Intrusion Barrier Analysis and Recuperation | The automobile industry is making huge strides to improve vehicle and occupant safety. A lot of safety improvements and modifications have been made in the past decade. But the side impact is still overlooked as not much has been improved for side safety despite most of the accidents and collisions happen to the side of a vehicle. Door intrusion barriers are the primary protection feature along with A, B and C pillars. Crashworthiness mainly depends on the position, cross-section and material of the intrusion barrier. So, our work mainly focuses on finding the optimum position, choosing the correct cross-section and finding the right material for the intrusion barrier. The objective of this project is to minimize the damage to the side of the vehicle by increasing its crashworthiness thereby reducing passenger injuries. A model of a vehicle door has been designed in Solid Works and various cross sections of door intrusion barriers like circular, rectangular, H-section, I section, E and C section have been developed. The crash test has been conducted according to New Car Assessment Program (NCAP) norms and the best possible configuration with highest safety level has been found. The barrier developed successfully reduced deformation by 36.667% and was subjected to a much lesser stress which was 28% lower than the existing barriers. |
Virtual Simulation of Door Slam Test, Study of Relative Sensitive Parameters and Correlation with Physical Test | Door slam test is one of the important durability tests in door design and development. Door requires to meet certain performance requirements like it should close properly (no metal to metal contact), there should not be any leakage, and closing operation should be smooth & with minimal effort and it should survive the life of the vehicle. Virtual simulation of door slam test, correlation with physical test results and effect of various parameters like seals stiffness are demonstrated in this study. Slam Analysis was carried out in LS-Dyna solver before physical test. This not only helped in avoiding initial structural design flaws, but also helped us in deciding door latch position, effect of mass distribution in the door and study of force distribution between primary seal, secondary seal and door latch. Primary and secondary seals played a critical role in the analysis. An intended length of both the seals was tested first to get its stiffness curve. Then it was modeled in the way that stiffness of one beam represented the stiffness of testing length. An in-house developed physical test was carried out for the intended cycles. A good correlation between simulation and test results is achieved. Overall detailed study of door slam test, simulation methodology and effect of various relative parameters on performance has become very important step in design and development of door assembly. |
Automotive Door Opening Durability Simulation Using Detail Checkstrap Mechanism | In automotive design space, door opening durability is one of the important design attribute to build a door structure. Customer often interact with door while ingress and egress a vehicle and that builds a perception of vehicle in customer’s mind. Now days, Computer Aided Engineering (CAE) is used extensively to simulate the real time door opening and closing event for designing the door structure for durability performance. Early prediction of durability performance and developing the countermeasures saves great amount of time and cost. This paper provides a brief study of detail checkstrap mechanism and its influence on door durability performance. Door checkstrap plays an important role in swing door design, it assists the door opening and closing with the help of check arm profile guided by roller and spring. This allows the load transferred from door to body through checkstrap first and then through hinges. The load interval between door full open to door over-open becomes critical for door durability performance. During this event, the majority of energy absorbed by the checkstrap mechanism and attached door & body components. Hence, the checkstrap mechanism representation is very important for the door durability simulation. Door dynamic analysis for overopen load is performed in LSDYNA solver and fatigue analysis is performed in nCode. |
A Robust Structure Analysis on Automotive Door Armrest | An automobile door is one vital commodity which has its role in vehicle’s function, strength, safety, dynamics and aesthetic parameters. The door system comprises of individual components and sub-assemblies such as door upper, bolster, armrest, door main panel, map-pocket, handle, speaker and tweeter grille. Among them, armrest is an integral part which provides function and also takes care of some safety parameter for the customers. The basic function of an armrest is to provide ergonomic relief to occupant for resting his hand. Along with this, it also facilitates occupant safety during a side impact collision by absorbing the energy and not imparting the reactive force on occupant. Thus an armrest has evolved as a feature of passive safety. The armrest design should be stiff enough to withstand required elbow load condition with-in the acceptable deflection criteria. On the other hand, armrest has to absorb the dynamic force by deflecting proportionally to the side impact load. In this study the various structure of armrest was analyzed to strike an ideal zone between functional and safety parameters. The scope is to improve the functional requirement, i.e., the side impact metrics and also to reduce the variation among the noise factors such as manufacturing tolerance, location of side impact and BIW rigidity. For this, DFSS way of approach is handled to optimize a robust design which provides enhanced passive safety for customer. This optimized passive safety armrest design can be used for upcoming programs and the development lead time can be reduced considerably. |
A Study of Design Methodology to Develop Improved Door System of a Vehicle | In the past few years, technological innovations in the automobile industry took vehicle performance to the next level. One such innovation is frame integrated panel door. This type of door helps automobile companies to have the advantages of both conventional panel and frame type doors. Though it has a good number of advantages, there are some drawbacks too. It requires improvements in its quality, NVH performance, weight and etc. Quality of a door is low due to the limitations in structural design and manufacturing technologies. And it is difficult to have a robust structure which leads to degradation of key performing factors such as NVH. For a lightweight vehicle, it is important to design an optimized structure for saving weight, without compromising its performance. In order to overcome these drawbacks a new optimized design structure is required for door system. This Research paper is about a systematic design methodology for Development of a new optimized door structural design by a comprehensive engineering design analysis of existing design constrains and drawbacks. The design methodology is described as below. Step 1 is the System analysis. The correlation of all components constituting the door was schematized and their functional relationships were modeled to analyze door system. Step 2 is the Problem analysis. The occurrence-sequence mechanism for problems was enumerated and the root cause was analyzed by investigating up to the sub ordinate level components in door system. Step 3 is deriving the concepts. Using the theory of inventive problem solving techniques, new concepts were derived from a variety of parameters such as new structures, materials and manufacturing processes. Step 4 is the Specification optimization. New design is evaluated for possible optimization in its specifications. Based on evaluation result optimal specifications are selected. Step 5 is the performance evaluation. The performance is verified by evaluating the new structure of the system. Following the above design process, a new door system with an initial design objective was developed. |
A Development of the New Mechanism for Preventing Door Opening in Side Impact Test | During a new vehicle development process, there are several requirements for side impact test that should be confirmed. One of the requirements is the prevention of door opening during side impact test. Even though there are many causes for door opening problem, this study deals with inertia effect by impact energy. Until now, there have been two classical methods to prevent car door from opening in side impact. One is the increment of the inertia resistance by increasing the mass of the balance weight and the spring force. The other is the application of the blocking lever. Unfortunately, in spite of our efforts, the door opening problem occurs occasionally. Therefore, to improve the problem fundamentally, this paper proposes a new blocking lever mechanism that work similar to ball-point pen structure. The proposed mechanism fixes the blocking lever when the opening directional inertia force is applied to the door outside handle during side crash. With this, it is possible to prevent vehicle door from opening during side impact. Additionally, it is possible to reduce the weight of door outside handle and the spring force. |
Multidisciplinary Design Optimization of Automobile Tail Door | Stringent emission norms by government and higher fuel economy targets have urged automotive companies to look beyond conventional methods of optimization to achieve an optimal design with minimum mass, which also meets the desired level of performance targets at the system as well as at vehicle level. In conventional optimization method, experts from each domain work independently to improve the performance based on their domain knowledge which may not lead to optimum design considering the performance parameters of all domain. It is time consuming and tedious process as it is an iterative method. Also, it fails to highlight the conflicting design solutions. With an increase in computational power, automotive companies are now adopting Multi-Disciplinary Optimization (MDO) approach which is capable of handling heterogeneous domains in parallel. It facilitates to understand the limitations of performances of all domains to achieve good balance between them. The paper presents the MDO of a Tail door of a sports utility vehicle (SUV) which is carried out at the stage where major structural design has been finalized, and the only gauge of the tail door panels can be taken for design variables. The objective of the exercise was to minimize the mass while meeting various performance parameters. Modal and frequency response function (FRF) load cases are considered for noise vibration and harshness (NVH) domain and stiffness load cases for durability domain. Crashworthiness domain load cases for the tail door were not considered here because crash norms are not applicable for rear impact. Response surface based optimization method has been selected for the optimization considering resource availability and dexterity of being applied in various domains. A sensitivity study was used to identify critical panels for each performance parameter. Broken constraint charts were studied to identify the load cases which limit the mass reduction opportunity. The study showed twelve percent of mass saving which is significant for automotive doors. |
Effect of PVC Skin and Its Properties on Automotive Door Trim Inserts | Plastic plays a major role in automotive interiors. Till now most of the Indian automobile industries are using plastics mainly to cover the bare sheet metal panels and to reduce the weight of the vehicle along with safety concerns. Eventually Indian customer requirement is changing towards luxury vehicles. Premium look and luxury feel of the vehicle plays an equal role along with fuel economy and cost. Interior cabin is the place where aesthetics and comfort is the key to attract customers. Door Trims are one of the major areas of interiors where one can be able to provide premium feeling to the customer by giving PVC skin and decorative inserts. This paper deals with different types of PVC skins and its properties based on process constraints, complexity of the inserts. Door trim inserts can be manufactured by various methods like adhesive pasting, thermo-compression molding and low pressure injection molding process etc. Considering process feasibility and PVC skin manufacturing constraints, it will be a challenge to decide the specifications of the PVC skin to achieve good quality product. The objective of this paper is to review the effect of PVC skin & its properties on door trim inserts using Low pressure injection molding and discuss steps involved in selecting the appropriate PVC skin. |
A Study on Optimization of the Ride Comfort of the Sliding Door Based on Rigid-Flexible Coupling Multi-Body Model | To solve the problem of serious roller wear and improve the smoothness of the sliding door motion process, the rigid-flexible coupling multi-body model of the vehicle sliding door was built in ADAMS. Force boundary conditions of the model were determined to meet the speed requirement of monitoring point and time requirement of door opening-closing process according to the bench test specification. The results of dynamic simulation agreed well with that of test so the practicability and credibility of the model was verified. In the optimization of the ride comfort of the sliding door, two different schemes were proposed. The one was to optimize the position of hinge pivots and the other was to optimize the structural parameters of the middle guide. The impact load of lead roller on middle guide, the curvature of the motion trajectory and angular acceleration of the sliding door centroid were taken as optimization objectives. In the first scheme, multiple sets of sample models were obtained by using orthogonal experimental design and approximate surrogate models were established with the method of RSM, Kriging and RBF. However, the optimum solution couldn’t be obtained because the optimization objectives are highly nonlinear with respect to the design variables. To solve the problem, an improved optimization method of hierarchical encryption was adopted and obtained the optimum solution finally. In the second scheme, the structural parameters with the best ride performance was obtained by using the evaluation function method. The proposed study improves not only the ride comfort of the sliding door, but also has great significance for the preliminary design and development of the sliding door. |
Minimizing the Rattling of Door Glass | Significant effort has been expended to improve the sound made by a closing car door. This study focuses on reducing door glass rattle sounds, not only evaluating the rattle influence of door glass support but also introducing an approach to reduce glass rattle noise by using sealing components. The first part of the study is dedicated to minimizing vibration. A jig is constructed to evaluate the influence of a door glass support on the rattling. The jig is employed so that the glass meshing between the A and B pillars can be controlled; the glass holder moves in the x- and z-directions and the belt molding moves in the y-direction. An impact hammer test was adopted for investigating door glass rattle. The frequency response obtained via impact hammer testing is analyzed by varying the glass support points and important factors that should be considered in early design stages are obtained. The second study is about optimizing vibration absorption. A glass run, door-side weather-strip, and body-side weather-strip are used to absorb vibration. The glass run section is created through the TRIZ technique. Performance evaluation of the rattle in this section show that the damping speed improved by 35% compared with the damping speed of the existing glass run, rendering it possible to significantly reduce glass rattle noise. This study suggests an approach to reducing both the vibration caused by DR BIW and door glass rattle noise using weather-strips. This research also shows that the door-side weather-strip is the most useful in reducing rattle noise. This study provides greater insight and access to the door glass rattle problem. |
Door Audio Response Hybrid Modeling and Assesment | The door response to audio excitation contributes to the overall performance of the audio system on several items. First, acting as a cabinet, it influences the loudspeaker response. Second, due to the door trim inner panel radiation, the radiated power is disturbed. A third effect is the regular occurrence of squeak and rattle, that will not be considered at this stage. Design issues regarding these attributes are numerous, from the loudspeaker design to door structure and trim definition. Modeling then appears as an unavoidable tool to handle the acoustic response of the loudspeaker in its actual surrounding. Since most of the issues are related to low frequency excitations (<200 Hz), and considering the fact that several loudspeaker references may be used in the same door, it was chosen to model the system in a hybrid manner: the electro-dynamical behavior of the speaker is modelled using a classical 1D modelling (Thiele and Small) while the door vibro-acoustic behavior is modelled by means of Finite Elements. After the vibroacoustic coupling between the loudspeaker and the door is fully described, transmission paths are investigated, showing possible simplifications. Electroacoustical indicators are then proposed to control the door design regarding audio quality issues. Sensitivity of the indicators to some design variables will then be shown. |
Simplified CAE Model Technique to Predict Crush Performance of Identical Sized Passenger Vehicle Doors | This paper highlights a simplified CAE model technique, which can simulate and predict door crush strength performance quickly. Such quick models can be used for DFSS and Design change studies. The proposed method suggests an equivalent sub model technique using only the door beam with tuned stiffness end springs to predict FMVSS214S full vehicle crush performance. Such models can be solved in minutes and hence very useful for DFSS studies during product design. The proposed method can be used to finalize door beam design for identical size of vehicle doors to meet required FMVSS214S crush performance. The paper highlights the door beam end springs tuning for identical size of cars and SUVs. Four vehicles were considered for the study. A single spring F-D (force -displacement) is tuned which correlated well for frond door of all the four vehicles. A separate unique spring F-D was needed which correlated well for rear door of all the 4 vehicles. |
A Research on the Prediction of Door Opening by the Inertia Effect during a Side Impact Crash | The purpose of this study is to develop a dynamic model that can accurately predict the motion of the door handle and counterweight during side impact crash tests. The door locking system, mainly composed of the door outside handle and door latch, is theoretically modeled, and it is assumed that the door outer panel can rotate and translate in all three directions during a side impact crash. Additionally, the numerical results are compared with real crash video footage, and satisfactory qualitative agreement is found. Finally, the simplified test rig that efficiently reflects the real crash test is introduced, and its operation is analyzed. |
Effect of Beam Layout and Specification on Side Door Strength of Passenger Cars: An Experimental Approach to Analyze Its Effect and Contribution to Door Strength. | Risk of injury to occupant in the event of side impact is considerably higher compared to frontal or rear impact as the energy absorbing zones at the front and rear of vehicle is high whereas limited space is available to dissipate the impact energy in the event of side impact. In such scenario strength of side door plays an important role in protecting the occupant. Side door beam in door structure contributes significantly towards the lateral stiffness and plays dominant role in limiting the structural intrusion into passenger compartment. Hence it is interesting to understand the effect of beam specification and orientation on side door strength. Since these factors not only affect the strength but also the cost and weight targets, their study and analysis is important with respect to door design This paper showcases the effect of beam layout and its specifications on the overall strength of the door with an experimental approach using physical test. Beams with different specification and orientation were tested and based upon the test results; a co-relation is built with Side door intrusion test as per IS 12009 |
Simulation and Physical Measurement of Seamless Passenger Airbag Door Deployment | Seamless Passenger Airbag Door, which means the seam of the passenger airbag door is not visible to the passenger, is being frequently implemented in the instrument panel because of its good surface appearance. But it is always a challenge to design a robust passenger airbag door with an invisible seam because many kinds of failures are possible during the design, such as cracks of the substrate of instrument panel, hinge failure of airbag door, windshield breakage, etc. Besides the engineering difficulties, the simulation of seamless passenger airbag door deployment is challenging due to three aspects: 1. the simulation method of the early stage airbag deployment (0~20 msec after trigger), 2. the material model of the airbag door pre-weakening line (the invisible seam); and 3. the physical measurement of the reaction load between cushion and door. In this paper, the FPM (Finite Point Method) method in PAM-CRASH™ was used to simulate the early stage airbag deployment and the fabric material model was validated by a material sample tensile test. An airbag deployment test was designed to push a mass upwards and the acceleration of the mass was measured. The measured acceleration shows FPM method with the validated fabric material model is capable to give a good prediction of the early stage airbag deployment. The material model of door seam is also presented and validated with a physical test. To measure the reaction load between airbag cushion and door, Flexi-Force™ sensors, film-like pressure sensors, were used. To deal with the nonlinear signal output of the sensor in different pressure ranges, a calibration device was developed exclusively for this sensor. After the calibration, 32 Flexi-Force™ sensors were put into a seamless passenger airbag door on the IP structure, and then the reaction load between the airbag door and the cushion was measured in its deployment. The action point position of the resultant reaction load, its peak value and duration correlate with the physical tests. Finally, the limitations and future developments are discussed. |
Study of Side Door Intrusion Test Results | With Ever Increasing Vehicle speed and Vehicle concentration on roads the number of accidents is also increasing. Safety and Strength of Vehicle has become a prime focus in Automobile Industry. The endeavor is to make a safe vehicle which would ensure occupants safety during collision. In Automotives, door system strength plays a vital role in defining the vehicle response during accidents. These accidents through, side door intrusion test and dynamic side impact test are simulated in the vehicle development cycle. Strength of the door required to meet these test criteria is dependent on the door beam, reinforcements, beam layout, vehicle construction and materials selected. There is not a fix method for door beam selection and design. Hence, it becomes all the more difficult to design and layout door beam and other reinforcements. In this paper we will discuss, challenges faced in a layout of door beam for a new vehicle program. Limitation in use of CAE analysis for achieving actual results, and design & layout modifications to be carried out to meet side door intrusion criteria effectively. |
Efficient and Light Weight Door Panels for Automobiles | Automobile manufacturers in the developing nations tend to make more and more fuel efficient cars compared to the luxurious type, given to the popularity. Fuel efficiency has a direct relation with the weight of the vehicle. In order to increase the fuel efficiency, body weight has to be decreased. The weight of all door panels comprises about 15% of body weight of the vehicle. Hence, by reducing the weight of the door panels, fuel efficiency of a vehicle can be increased. But, reduction of the weight of the door panels may lead to decrease in the strength of the panels. Therefore, we need to find a method to increase the fuel efficiency by decreasing the weight and maintaining the strength of the door panels. The aim of our study is to increase the performance while decreasing the weight of the door panel assembly. We have used CAE (Computer aided Engineering) as a tool to study and evaluate the performance of doors, with varying thickness and different shapes like beads. We found different methods to strengthen the panels by modifying the shape. It was concluded that reduction in the weight of the door can be done by improving the shape and performance of the door. |
Structure to Assist in the Prevention of Bimetallic Corrosion of Hybrid Doors | The use of low-density materials in body panels is increasing as a measure to reduce the weight of the vehicle body. Honda has developed an aluminum/steel sheet hybrid door that is more effective in reducing weight than an all-aluminum door. Because aluminum was used in the door skin, bimetallic corrosion at the connection between the aluminum and the steel sheets represented an issue. It was possible that the difference in the electrical potential of the two metals might promote corrosion at the connection between the aluminum door skin and the steel sheet door panel, in particular at the lower edge of the door, where rainwater and other moisture tend to accumulate, with the result that the appeal of the exterior of the door might decline. To address this issue, a watertight structure realized through the use of a high-ductility sealer was employed in order to help prevent water from infiltrating to the connection between the metals, and steel sheets with a zinc-aluminum-magnesium alloy coating, highly effective in controlling bimetallic corrosion, were employed in the door panels. This produced rust-resistance specifications for the hybrid door able to maintain durability in market use environments. This paper discusses the effect of the zinc-aluminum-magnesium alloy-coated steel sheets in controlling bimetallic corrosion. |
Finite Element Analysis of Door Closing Effort | The door closing effort is one of the first impressions to customer's mind about the engineering and quality of the vehicle. The door closing force and the minimum door closing speed are two important characteristics for evaluation. But we can obtain these two indices only by experiments and/or subjective assessments. To predict the door closing effort by the simulation method during the design phase, a finite element analysis model is established. The compression load deflection behavior of seals is converted to the parameters of constitutive model of seals by the parameters identification method. Then, the seal resistance force and the minimum door closing speed are calculated. The later correlates very well with the experiment data. |
A Study on the Rattle Index from a Vehicle Door Trim under Audio System Inputs | The sound inside a passenger cabin is composed of many elements, which include irritating noises such as buzzes, squeaks and rattles. Customer perception of buzz, squeak and rattle (BSR) is measured by Things Gone Wrong (TGW), warranty claims and JD Power surveys.1) The Speaker BSR test has been adopted to evaluate and to eliminate rattle noise of a door module while playing sound through the audio system. Subjective listening had been the preferred method for rattle noise detection, due to the sound of the audio system in any measurement. In this paper a quantitative approach for the rattle noise under the speaker test is proposed. The HANIL E-HWA rattle index was developed using a high pass filter, hiss noise reduction filter, SPL data with short time constant, peak value and fluctuation. The high pass filter was adopted to separate the rattle noise from the speaker sound, due to much higher sound pressure level [108 dB(A)] in the latter case. It is then possible to quantify the rattle noise by the HANIL E-HWA rattle index based on the peak values and fluctuations of the SPL data in the speaker BSR test. This article includes test results which show the improved rattle noise detection capability of the HANIL E-HWA rattle index. |
A Method of Designing Automotive Door Glass and Guide Rail based on the Drum Surface | A new method based on the drum surface is proposed to fit the dual-curvature glass. The drum surface is obtained from the automotive body cloud data with the kinematic equation using line element geometry and K-Local-RANSAC algorithm. Then the guide rail curve is obtained by the proportional function method based on the drum curve principle. At last, the motion deviation of the glass is analyzed and the maximum motion deviation is not more than 0.6mm. The results have completely achieved the engineering requirements, which prove that the method of fitting the glass and the guide rail is correct and reasonable. |
Study of Optimizing Sliding Door Efforts and Package Layout | A sliding door is one of the car door systems, which is generally applied to the vans. Compared with swing doors, a sliding door gives comfort to the passengers when they get in or out the car. With an increasing number of the family-scale activities, there followed a huge demand on the vans, which caused growing interests in the convenience technology of the sliding door system. A typical sliding door system has negative effects on the vehicle interior package and the operating effort. Since the door should move backward without touching the car body, the trajectory of the center rail should be a curve. The curve-shaped center rail infiltrates not only the passenger shoulder room, but also the opening flange curve, which results in the interior package loss. Moreover, as the passenger pulls the door outside handle along the normal direction of the door outer skin, the curved rail causes the opening effort loss. In this study, we discuss not only how the curved center rail causes negative effects on the vehicle interior package and the manual operating effort, but also how to effectively improve and optimize the sliding door system. Moreover, we propose a new design concept of a convenient sliding door system. By applying a straight center rail and a latch with a multi-link structure, we were able to decrease the center rail infiltration. Also, the performance of getting on and off the 3rd row was improved, and the manual operating effort was improved about 60%. |
Vehicle Door Inner Frame Part Design with Knowledge-Based Engineering | In this study, a computer-aided design (CAD) geometry system that is linked to each other to create a parametric form of the side rear door’s inner frame sheet piece on a passenger vehicle body in a Siemens NX environment was developed. The system was created in the NX CAD environment, using the program’s unique product development structure. The system was designed and modified for time-consuming parts. At the end of the study, the parameterized vehicle door geometries worked in the NX environment standardized the design process and accelerated the design works. |
Classification of Contact Forces in Human-Robot Collaborative Manufacturing Environments | This paper presents a machine learning application of the force/torque sensor in a human-robot collaborative manufacturing scenario. The purpose is to simplify the programming for physical interactions between the human operators and industrial robots in a hybrid manufacturing cell which combines several robotic applications, such as parts manipulation, assembly, sealing and painting, etc. A multiclass classifier using Light Gradient Boosting Machine (LightGBM) is first introduced in a robotic application for discriminating five different contact states w.r.t. the force/torque data. A systematic approach to train machine-learning based classifiers is presented, thus opens a door for enabling LightGBM with robotic data process. The total task time is reduced largely because force transitions can be detected on-the-fly. Experiments on an ABB force sensor and an industrial robot demonstrate the feasibility of the proposed method. |
Novel Glass Laminates for Improved Acoustic Performance | Noise, Vibration, and Harshness (NVH) performance of vehicles is an all-encompassing study of hearing and feeling vibration as it relates to end user experience. The collection of glass in a vehicle can represent a large surface area, and can have a significant effect on NVH performance. Some of the most important glazing positions in relationship to the driver are the front doors, due to the proximity to the driver. Novel glass laminate constructions can provide acoustic improvement for these body positions over typically used standard glazings. The performance of these constructions will be discussed in terms of: acoustics, glass closing and door slam survivability, and solar performance. |
Research on Intelligent Layout of Door Hinge Based on CATIA CAA | As one of the most important auto-body moving parts, door hinge is the key point of door design and its accessories arrangement, also the premise of the door kinematic analysis. We proposed an effective layout procedure for door hinge and developed an intelligent system on CATIA CAA platform to execute it. One toolbar and five function modules are constructed - Axis Arrangement, Section, Parting Line, Kinematic, Hinge Database. This system integrated geometrical algorithms, automatically calculate the minimum clearances between doors, fender and hinges on sections to judge if the layout is feasible. As the sizes of the clearances are set to 0s, the feasible layout regions and extreme start/end points are shown in parts window, which help the engineer to check the parting line and design a new one. Our system successfully implemented the functions of five modules for the layout of door hinge axis and parting line based on a door hinge database. An instance is carried out and the result shows that our system has great feasibility and validity to arrange the door hinge and shorten the design periods. |
Door Closing Sound Quality Methodology - Airborne and Structural Path Contributions | The intent of this paper is to document comprehensive test-based approach to analyze the door-closing event and associated sound using structural and acoustic loads developed during the event. This study looks into the door-closing phenomenon from the structural interaction point of view between the door and the body of the vehicle. The study primarily focuses on distributing the door and body interaction as discrete multiple structural and acoustic phenomena. It also emphasizes on the structural and acoustic loads developed by the discretized interactions at the interfaces between the door and the body frame. These interfaces were treated to be the load paths from the door to the body. The equivalent structural and acoustic loads were calculated indirectly using the well-known Transfer Path Analysis (TPA) methodology for structural loads and the Acoustic Source Quantification (ASQ) methodology for acoustic loads. Considering the transient nature of the door-closing event, a time domain TPA methodology was also developed to study the loads being developed between the latch, the striker and the different interfaces of the door frame to the body structure. Similarly the equivalent acoustic loads were developed at the interfaces between the door frame and the body. Computed time domain and frequency domain loads were used to perform a partial contribution analysis from different paths and identify the contribution of the structural and acoustic loads and paths on the target response at the center of the operator's ear (COE) located the outside of the vehicle. |
Five Bonding Techniques of Side Door Trim Insert Skin Decoration | Interiors of past vehicles were created to satisfy specific functions with appearance being a secondary consideration, but in the present & future market with ever increasing vehicle luxury, decoration of vehicle has become a prime focus in automobile industry along with the safety & economy. Automotive interiors have evolved over the years from a collection of trims covering bare sheet metal panels to add quality & richness of interior cabin, ultimately delivering greater value to customers. One such area in interiors is Side door trims serving the dual purpose of functionality and creating a pleasing environment too. The aesthetic appeal to the Side door trim is added usually through a Door trim insert having a decorative skin pasted on to the plastic base. And the selection of pasting technique for pasting decorative film on to the plastic base insert is a challenge for an automotive interior designer. The objective of this paper will be to review technologies available for manufacturing Door trim inserts with decorative skins, and discuss a direction toward selecting an appropriate pasting technique with cost effectiveness. In automotive industry, for Side door trim insert decoration, five bonding techniques are used ranging from Adhesive pasting, Thermo compression molding using natural fiber reinforced PP, Pressure lamination, Kimikomi, and Low pressure injection molding, all these will be discussed in this paper. A brief synopsis of the advantages and disadvantages of each process including cost effectiveness, design considerations, shape & complexity of Door trim inserts, Door trim insert skin types & their physical property requirements, process considerations and its testing methods are covered. In addition to this, the necessary tooling investment will also be discussed in this paper. |
A Component Test Methodology for Simulation of Full-Vehicle Side Impact Dummy Abdomen Responses for Door Trim Evaluation | Described in this paper is a component test methodology to evaluate the door trim armrest performance in an Insurance Institute for Highway Safety (IIHS) side impact test and to predict the SID-IIs abdomen injury metrics (rib deflection, deflection rate and V*C). The test methodology consisted of a sub-assembly of two SID-IIs abdomen ribs with spine box, mounted on a linear bearing and allowed to translate in the direction of impact. The spine box with the assembly of two abdominal ribs was rigidly attached to the sliding test fixture, and is stationary at the start of the test. The door trim armrest was mounted on the impactor, which was prescribed the door velocity profile obtained from full-vehicle test. The location and orientation of the armrest relative to the dummy abdomen ribs was maintained the same as in the full-vehicle test. An aluminum honeycomb of a pre-determined crush strength and cross-sectional area attached to the base of the assembly of two abdominal ribs was used to simulate the lumbar shear force, to capture the effect of lower torso loading on the upper torso. The test methodology was developed and validated to a full-vehicle test and the sensitivity of the methodology to different armrest designs was also evaluated. The results show good correlation to full-vehicle test, thus indicating that this component test methodology has good potential to evaluate different armrest design alternatives across various vehicle programs. |
An Experimental Study on Flow Pattern of Door Trim Speaker Grille Shape | Recently the automotive industry has focused on reducing product development time to correspond with the customer's demands. Especially when quickly changed. The decreased product development time shortens the quality assurance period. It makes difficult to guarantee the quality of the products. The improved quality assurance is required so that customer's expectations are actually higher quality than in the past. Most automotive interior parts are manufactured by using plastic. It is very sensitive to focus on quality, because it is exposed to a passenger's sight. So automotive interior companies make full use of injection molding CAE in an effective ways to reduce costs and reduce elements of poor quality. This paper suggests a methodology that improves reliability for injection molding analysis in grille shapes of door trim. And it involves an experimental analysis of flow pattern in speaker grille shapes. To analyze it, use an authentic mold of speaker grilles in door trim and Mold flow software. |
CAE Simulation of Door Sag/Set Using Subsystem Level Approach | The performance of door assembly is very significant for the vehicle design and door sag/set is one of the important attribute for design of door assembly. This paper provides an overview of conventional approach for door sag/set study based on door-hinge-BIW assembly (system level approach) and its limitation over new approach based on subassembly (subsystem level approach). The door sag/set simulation at system level is the most common approach adopted across auto industry. This approach evaluates only structural adequacy of door assembly system for sag load. To find key contributor for door sagging is always been time consuming task with conventional approach thus there is a delay in providing design enablers to meet the design target. New approach of door sag/set at “subsystem level” evaluates the structural stiffness contribution of individual subsystem. It support for setting up the target at subsystem level, which integrate and regulate the system level performance. This approach is also useful for generating the design enablers and for optimization of door-hinge-BIW assembly with higher reliability. The commercial software “ABAQUS STANDARD” is used as FE solver to simulate the door sag/set by both the approaches with application of material, geometrical and contact nonlinearities. |
Experimental Approach to Improve the Door Slam Noise Quality in Utility Vehicles | The customer perception about the door slam noise and its feel would indicate the brand image of the car. In this paper the authors have made an effort to improve the door slam noise quality of the vehicle, which is currently in production. This paper describes the probable areas in the door to improve the slam noise quality by attempting modifications in the door design factors, such as door alignments, door panel stiffness, door trims, window glass rattle, latch striker alignment, door seals, air extractor. Since the door closing event is a transient phenomenon, it requires special tools such as wavelet transforms, Zwicker loudness to understand the slam events precisely. Subjective jury evaluations have been conducted to understand the effect of these modifications and rank the modifications based on their contributions to the door slam quality. |
French Door Open/Close Durability Evaluation by Multibody Dynamics Method | A method including Multi-Body Dynamics (MBD) and fatigue assessment process with modal approach was developed to predict Light Commercial Van (LCV) Rear French Doors open/close durability performance during early design stage to improve test detect ability. The nonlinear properties of joints, such as those on bolted housings or spot welds sheets and hem flange areas, can substantially influence the local and global results of a dynamic simulation. The Modal approach considers joint contact, by way of Joint Interface Modes (JIMs) by using Contact Subroutine (MAMBA) to co-simulate with MBD software to improve result quality. One of the main challenges is measuring the dynamic stiffness for the weather strip. A novel test method was used to measure the weather strip dynamic stiffness by conducting an “in-situ” test. For CAE simulation results, positive feedback was received from design and test engineers. |
Study of the Energetic Influence of Each Component Responsible for Closing the Side Doors | Currently, studies are being developed by automobile engineers about the energy required by the client during the closing door of the car. This paper proposes an analysis of A segment vehicle, four doors, in order to evaluate the influence of each component of the door/body responsible for closing the side doors. Tests will be carried out to demonstrate exactly the contribution of the door sealing, exhaust air valve and the inner cabin air pressure effect, door link, hinges and latch, plus the actual weight of the door during the closing. The results show which are the door/body components most responsible for car door closing movement energy increase and still, where to direct efforts to provide greater comfort for customers. |
Integration and Lightweight Design in Automotive Doors | Future doors require light weight, cost efficient and acoustic optimized solutions. Current steel doors offer only a small range of possibilities in these areas. With the use of aluminum doors the weight will be reduced but production complexity and costs will be increased. A modular door approach supports all of these future demands. Door modules have set milestones for door concepts in the past. Due to technological progress, door modules are more relevant in the current scenario. The use of reinforced plastics allows a high degree of design freedom with high integration of features.[2] In addition to weight reduction of up to 1.5kg per door the complete production process comes leaner with a higher grade of quality. The acoustic performance of a door system can be adjusted for noise reduction and improvement of the sound quality of speakers as illustrated. Functional integration is the key driver of weight and cost reduction |
A Study on Prediction of Door Deformation in High Speed Passenger Vehicle at Cross Wind | In this study, several design factors are considered to predict door deformation. Door deformation is mainly influenced by air flow around A-pillar and door static stiffness. Therefore design factors can be divided into two categories. First, design elements determined by the appearance of a car affect to the air flow around A-pillar. Second, door static stiffness is determined by engineering design parameters. Kriging method is used to predict door deformation by means of the design factors. Door deformation can be successfully predicted with this method. |
Modelling and Simulation of Door Control System | A Door Control System is being used for controlling doors in buses running in urban/suburban areas as a part of safety requirement and to protect the passengers. The opening and closing of the doors will be in logical sequence depending upon the driver input, vehicle speed and the emergency conditions. To achieve this logic the door control system consists of an ECU, pneumatic valves, pressure sensors and switches. To predict the performance of this system under various operating conditions, the entire system is being modeled in one of the commercially available multi-domain physical modeling software employing bond graph technique and lumped system and the performance is predicted. This paper deals with the modeling and simulation of entire Door Control System. |
Investigation of Relation between Sub System Level (Quasi-Static) Side Door Intrusion to Side Collision Test | With the change in the perspective of the Customers towards safer vehicles, most of the Vehicle manufacturers in India are making their vehicles Crash compliant. According to the accidental data collection, Side crashes are second leading cause of death after Frontal crash. Currently sub system level tests are done for evaluating the side impact safety performance of the vehicle. One of such sub system level test is Quasi-static side door intrusion Test. The primary purpose of this testing is to measure the Force-deflection characteristics by intrusion of the impactor into the vehicle. These characteristics are controlled by various door components like door beam, latch & striker, hinge etc. This article studies the relation between Side door intrusion and Side collision, effect of above mentioned components on this relation. A theoretical study is done to study this relationship and it is substantiated with experimental data. |
Study of Sliding Door Closing Speed for a Manually Operated Sliding Door | The door performance of an automobile is gauged not only by its function but also the “feel” of operating a door which majorly depends upon opening/closing force and closing speed. This feel is in direct relation to the soundness of design and the build quality which the customer experiences even before driving the vehicle. Several studies have been conducted for door open/close performance for a conventional swing door, however little has been done in direction of sliding door. In this paper an analysis of closing speed of manually operated sliding door in purview of various parameters affecting them and their individual and combined contribution at vehicle level is presented. As the closing locus of sliding door is different from a swing door, a special experimental setup is used to measure the closing speed of sliding door. |
MMLV: Door Design and Component Testing | The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of a US Department of Energy project DE-EE0005574. The project demonstrates the lightweighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefit and fuel reduction. This paper reviews the mass reduction and structural performance of aluminum, magnesium, and steel components for a lightweight multi material door design for a C/D segment passenger vehicle. Stiffness, durability, and crash requirements are assessed. The structure incorporated aluminum sheet, aluminum extrusion, magnesium high pressure vacuum die casting and steel sheet. The multi material components were assembled using structural adhesive bonding (hem and structure), self-pierce rivets (SPRs), single sided rivets, and bolts. The aluminum extrusion and the magnesium casting in the MMLV door were specifically designed to maximize stiffness, reduce part count and maximize mass reduction. To optimize the strength and weight of the MMLV door, a new aluminum intensive structure was developed. The new structure features a unique architecture that uses a multi-cavity aluminum extrusion joined to stamped sheet reinforcements to provide a direct load path between the hinges and the latch. The new structure also utilizes a high pressure vacuum die cast magnesium casting to create the structure at the base of the A-pillar on the front door to achieve the required structural stiffness while reducing components and maximizing the mass reduction. The “barn door” architecture of the inner structure of the door allowed for gage optimization of both the inner and outer stampings, the two largest and heaviest components of the assembly. Overall, the design architecture used in the MMLV doors allowed for a mass reduction of 33% through the use of multi material, gage optimization, and multiple forming technologies, while achieving all of the structural requirements. |
Numerical Study of Effect of Material and Orientation on Strength of Side Door Intrusion Beam | Nowadays more and more people are concerned about the safety rating of their vehicle. The safety rating depends on the ability of the car to minimize the injury to the occupants post-crash. Crashworthiness of the vehicle is determined by carrying out various tests such as static and dynamic tests. Side crashes are one of the leading causes of fatal injury following front crashes. Side door strength is dependent on the door components such as latch and striker, hinge, door beam etc. Lateral stiffness is contributed significantly by the side door beam in the door structure. The side door beam limits the side intrusion into passenger compartment. This paper emphasizes the effect of intrusion beam materials and orientation in the side door strength with a numerical approach using ANSYS tool. These factors affect the strength and weight of the door. The simulation study with respect to door design is cost-effective and time-saving. Side door intrusion test as per IS 12009 norms is simulated in the software and are substantiated by the experimental test results of existing literature. |
Vehicle Door Cutline Determination with Mathematical Modelling on CATIA V5 | Door shut-line definition is the first vital step in car body door engineering and depends on the hinge position, hinge shape, manufacturing capabilities and other parameters. In the design process, once the hinge axis definition is finalized door shut-line is defined which should satisfy two major requirements. The requirements are clearance between the door outer surface with its surrounding components (like hinges, fender, other door etc.) and assembly feasibility. Another one is the manufacturability of the proposed design. The above conditions must be checked on different locations of the door as well as w.r.t different openings of the door. The paper presents a mathematical model to determine the door shut-line position with great computational efficiency. This method propounds closure engineer with parameters to define the shut line rather than going for cumbersome manual iterative process. Instead of following an iterative approach to determine a limit for the shut-line, paper presents a mathematical formulation with an implicit equation. An innovative approach to solve implicit equation on CATIA is also discussed which significantly reduces the processing time. This paper inherently discusses a series of challenges which a user faces while determining the door shut-line and provides feasible solutions for those problems. |
CFD-Simulation and Validation of Cabin Pressure during Door Closing Motions | Under the competitive pressure of automotive industry the customer’s focus is on a vehicle’s quality perception. Side door closing efforts make a considerable share of the overall impression as the doors are the first physical and haptic interface to the customer. Customer’s subjective feeling of vehicle quality demands for detailed analysis of each contributor of door closing efforts. Most contributors come from kinematic influences. Beside the losses due to mechanical subsystems like the checkarm, latch or hinge friction one of the biggest impacts originates from the pressure spike that builds up due to air being pushed into the cabin. Subject of this publication is to discuss the dependencies of closing efforts on cabin pressure and air extraction. It demonstrates an approach to simulate the development of the air pressure during door closing motions and the validation of the simulation method with the “EZ-Slam” measurement device. In order to produce a correlation between simulation and reality a simplified model of a vehicle cabin is created. The validation tests are conducted on a physical test rig, built exactly according to the model, and the CFD simulation is done on the CAD model of the rig. In order to show a correlation between the CFD method and the physical test procedure a set of influencing parameters is identified and tested for its impact on the pressure spike. |
An Optimal Design of Vehicle Swing Door Using Metamodeling Techniques | In side-closures’ design, mass reduction provides numerous benefits in addition to reduced cost. This paper presents a Meta model based non-linear durability optimization to develop a lightweight structure for vehicle swing door. A surrogate model developed is using Kriging methodology and the thickness of the door components are given as input design variables. Adaptive Multi-Objective Genetic Algorithm (AMGA), a nonlinear optimization technique, is used in this study, to formulate the mass minimization under durability constraints. The optimized swing door design shows the overall mass saving of ~10% over initial design in terms of frame and sag deflection. The present investigation shows better effectiveness and practical applicability to develop the lightweight structure for the vehicle swing door. From the comparative study, Kriging method is found to be more effective in terms of measuring the accuracy, robustness and efficiency of the results than the Radial basis function (RBF). |
Development of the Wireless Power Transfer Technology for a Sliding Door | The sliding door’s movement is 3-dimensional unlike the conventional door. So the electric power and signal are exchanged via the long ‘Power Cable’. It has a quite complex structure in order to be suitable to connect the vehicle’s body and the sliding door even during it’s moving. As the result, it is more expensive than conventional door’s one and the quality could not be guaranteed easily. In this paper, I have developed new technology which could transfer electric power by ‘wireless transfer’ in order to resolve the problem from using ‘Power cable’. I would propose the proper structure to transfer the electric power at any position of the sliding door without any physical connection. To transfer the electric power which drives the window regulator and the actuators in door, I have applied the ‘inductive coupling’ system. And in order to decide the engineering properties - such as the dimensions of the core, the values of the electric elements and the frequency of the transferred electricity - a myriad of computer analysis and experiments under various conditions would be implemented. Finally, the optimal solution was figured out and it was validated under the real vehicle’s condition. This research would be adopted in various types of the future door system. |
A Study on Door Clips and Their Influence on BSR Performance | Squeak and rattle concerns account for approximately 10% of overall vehicle Things Gone Wrong (TGW) and are major quality concern for automotive OEM’s. Objectionable door noises are one of the top 10 IQS concerns under any OEM nameplate. Door trim significantly contributes to overall BSR quality perception. Door trim is mounted on door in white using small plastic clips with variable properties that can significantly influence BSR performance. In this paper, the performance of various door clips is evaluated through objective parameters like interface dynamic stiffness and system damping. The methodology involves a simple dynamic system for the evaluation of the performance of a clip design. Transmissibility is calculated from the dynamic response of a mass supported by clip. Parameters such as interface stiffness and system damping are extracted for each clip design. Variation of inner panel thickness is also considered when comparing clip performance. In a second step, clip characteristics are transferred to an equivalent finite element model to predict the response of mass supported by clip. The equivalent clip model is compared with generic clip model for analyzing squeak and rattle simulation in a door assembly. A satisfactory correlation has been achieved between measured and simulated response of clip. Design targets are finally presented for the selection of door clips in the product development process, to avoid rattle issues in door trim assemblies. |
Door Closure Sound Quality Engineering Process | An important factor contributing to a customer’s subjective perception of a vehicle, particularly at the point-of-purchase, is the sound created by the passenger doors during closure events. Although these sounds are very short in duration the key systems that control the sounds produced can be highly coupled. Similarly, the necessary efforts required to understand key design criteria affecting the sound can also be highly complex. Within this paper sub-systems affecting the door closure sound are evaluated to understand key structural properties and behaviors toward the contribution to the overall sound produced. This begins with the subjective preferences of typical sounds and the difficulties with both measuring and reproducing these sounds appropriately and leads directly to the target setting and target cascading process. With targets in place, it becomes important to link them with physical measurements of the vehicle and door system to identify the key controlling mechanisms that can be affected through design. The behavior of the door system during a closure event is key for the sound produced and can be studied to understand both the nearfield acoustic field generated as well as the structural vibration patterns. This can be accomplished during a closure event and linked to in-lab assessments that allow for greater repeatability and flexibility. Boundary conditions for the door structure are also relevant to the sound produced, including the transmission of forces into the seals, latch and striker, and bump-stops, as well as understanding the effects from the vehicle interior cavity. Once the key controlling mechanisms affecting the door closure sound quality are understood, it allows for the sound produced to be shaped as desired. This can be accomplished by leveraging analytical modeling efforts, supplemented with necessary test data, to design key components and systems to achieve the desired sound. |
Sound Quality Prediction Modelling for the Transient Sound of Vehicle Door Latch Closure | Door latch closure noise has contribution on sound quality of vehicle door slam sound. This paper focuses on the modelling of sound quality for door latch closure sound. 24 various latch closure sound samples were recorded to be evaluated subjectively. A novel Dynamic Paired Comparison Method (DPCM) was introduced for subjective evaluation. By eliminating the redundant comparison pairs the DPCM dramatically reduced the evaluation work load comparing to the traditional Paired Comparison Method (PCM). Correlation between subjective evaluation results and psychoacoustic metrics was analyzed to find out the most relevant metrics as inputs for the subsequent prediction model. Besides, the shudder effect induced by multi-impact of latch components during closing movement was also found strongly affecting the subjective perception of door latch closure sound. Therefore, a new metric Shudder Level which is graded in 3 levels describing this shudder effect was developed and then quantified as one of the model inputs. The sound quality of door latch closure was modeled by means of Multi-Linear Regression Function (MLRF) both with and without the Shudder Level. The results show that the model which takes the shudder effect into account gives a better prediction on door latch closure sound quality. |
The Analysis and Control of Aural Discomfort inside a Car at the Instant of Door Closing | With the continuous improvement of vehicle air leakage performance, an aural discomfort phenomenon had been occurred at the instant of vehicle door closing. There are many studies on door closing sound quality in past 20 years, but there is little publications on the study of the aural discomfort due to a transient high air pressure fluctuations. In this paper, the relationships of passenger’s aural discomfort produced by interior air pressure fluctuations are systematically studied. The ratio of door surface area to passenger compartment volume and other related parameters such as the cross-sectional area of a vehicle, the air extractor size, and the vehicle body air leakage under positive pressure are also studied through CAE analysis and verified through a large number of objective measurements and subjective vehicle evaluation. Base on this study, a new threshold value of air pressure fluctuation for human aural comfort, and a new objective evaluation index for aural discomfort due to the transient air pressure fluctuations are defined. Some guidelines for the pressure exhaust system design and development to improve the door closing aural comfort of passenger vehicles are provided. |
A Robust Methodology to Predict the Fatigue Life of an Automotive Closures System Subjected to Hinge and Check Link Load | In order to provide an accurate estimation of fatigue life of automotive door hinges and check strap mounting location, it is crucial to understand the loading conditions associated with opening and closing the door. There are many random factors and uncertainties that affect the durability performance of hinge and check strap mount structures in either a direct or indirect way. Excessive loads are generated at the hinge and check arm mounting region during abuse conditions when opening the door. Repeating the abuse conditions will lead to fatigue failures in these components. Most influencing parameter affecting the fatigue performance for the door was the loads due to hinge-check arm sensitivity stoppage and the distance between hinge and check strap attachments. However, the probability of occurrences was low, but the impact is high. In this proposed investigation, Monte Carlo simulation methodology is applied on the randomly selected samples with predicted distribution of all dependent factors to know the fatigue life variations in the hinge mount structure. Weibull distribution is the most efficient way of estimating the fatigue failure or fatigue life. This can be estimated on the basis of the function of the populated size. The mean and standard deviation of the simulated fatigue life converged with a greater number of randomly varied samples. This technique defines the maximum allowable load cycles on the hinges and the check arm mount structure, and their variability. It helps in keeping the door opening efforts below the target value. The fatigue life cycle of the door is predicted closest to the experiments by applying the proposed method on more number of samples. It also keeps the probability of failure under check |
A Study on Optimization of the Cross-Section of Door Impact Beam for Weight Reduction | This paper focuses on the optimization of the cross-section of a panel type impact door beam. The key parameters of the cross-section of the beam were artificially changed by using a geometry morphing tool FCM (Fast Concept Modeler), which is plugged in to CATIA. Then, the metamodel of FE (Finite Element) analysis results was created and optimized using LS-OPT. The ANOVA (Analysis of Variance) analysis of results was carried out to find the factor of weight reduction. Finally, a new cross section concept was proposed to overcome the limitation of old structure. The optimization was carried out for the beam with the final cross-section to have 10 % or more reduction in total weight. |
A Research on Kinematic Optimization of Auto Flush Door Handle System | Today, many car manufacturers and their suppliers are very interested in power-operated door handles, known as auto flush door handles. These handles have a distinguishing feature in terms of the way they operate. They are hidden in door skins and deployed automatically when users need to open the door. It is obvious that it is a major exterior styling point that makes customers interested in the vehicles that apply it. To make this auto flush door handle, however, there lie difficulties. First, because there is no sufficient space inside a door, applying these handles can be a constraint in exterior design unless the structures of them are kinematic optimized. The insufficient space can also cause problems in appearance of the handles when they are deployed. The purpose of this study is to establish the kinematic system of auto flush door handle to overcome the exterior handicaps such as the excessive exposure of the internal area on the deployed position. In order to resolve these issues, the Scott-Russell mechanism is applied to the auto flush handle system, and the key parameters are optimized by the methodology of DFSS dynamic characteristics method. Therefore, the engineering solutions are given to resolve the finger jamming in the handle due to the high speed retraction and the incongruity of the relative retraction speed between the handle and outside mirror. Thus, in this paper, the engineering solutions and optimized criteria to resolve all related issues are introduced to enhance the values of vehicles for customers. |
Robust Assessment of Automotive Door Structure by Considering Manufacturing Variations | The automotive door structure experience various static and dynamic loading conditions while going through an opening and closing operation. A typical swing door is attached to the body with two hinges and a check strap. These mechanisms carry the loads while the door is opened. Similarly, while closing the door, the latch/striker mechanism along with the seal around the periphery of the door react all loads. Typically, computer aided engineering (CAE) simulations are performed considering a nominal manufacturing (or build) tolerance condition, that results in one loading scenario. But while assembling the door with the body, the build variations in door mechanisms mentioned above can result in different loading scenarios and it should be accounted for design evaluation. This paper discusses various build tolerances and its effect on door durability performances to achieve a robust door design. |
CAE Simulation of Automotive Door Upper Frame Deflection Using Aerodynamic Loads | Upper frame deflection of automobile doors is a key design attribute that influences structural integrity and door seal performance as related to NVH. This is a critical customer quality perception attribute and is a key enabler to ensure wind noise performance is acceptable. This paper provides an overview of two simulation methodologies to predict door upper frame deflection. A simplified simulation approach using point loads is presented along with its limitations and is compared to a new method that uses CFD tools to estimate aerodynamic loads on body panels at various vehicle speeds and wind directions. The approach consisted of performing external aerodynamic CFD simulation and using the aerodynamic loads as inputs to a CAE simulation. The details of the methodology are presented along with results and correlation to experimental data from the wind tunnel. |
Evaluation of Energy Efficiency Performance of Refrigerated and Heated Van Semitrailers | The objective of this project was to provide pertinent information on the performance of refrigeration and heating transportation units to help fleets make decisions that will improve efficiency and increase productivity. To achieve this objective, tests were designed to measure the performance of selected refrigeration and heating units, mounted on refrigerated and heated van semitrailers. Cooling and freezing tests were carried out in summer conditions while heating tests were carried out in winter conditions, for various temperature settings. Two fundamental approaches were considered: the design of the refrigerated or heated trailer and the temperature setting of the refrigeration or heating unit. For cooling and freezing tests, the fuel consumption comparison between similar trailer models of different ages showed that newer units performed better than older ones. However, other factors such as trailer design, presence of a ventilation system, and type of insulation may also influence fuel consumption of such units. For refrigerated trailers of the same make and of similar age, those with swing doors performed better than those with roll-up doors with regards to both fuel consumption and insulation. For trailers with the same make of refrigeration unit, those without side doors performed better than those with side doors. For heating tests, it was observed that newer heated trailers with composite or insulated doors generally consumed 1.5 to 3 times less fuel then the older trailers with wood or metal doors. The tests confirmed that the interior temperature setting has a significant impact on the fuel consumption of the refrigeration or heating unit when the difference in set temperature is considerable. |
Effect of Hinge Axis Inclination and Hinge Tolerance on Door Strength under Abuse Loads | As revealed from J. D. Power surveys, today most vehicle owners consider perceived quality as a direct indicator of the vehicle build quality and durability. [5] The problem has become more prominent and noticeable in recent times, due to the desire for reduced cost, reduced weight targets, aesthetic demands, and crash requirements. The performance of the door assembly when subjected to an abuse load of sag and over opening is one such perceived quality indicator which gives the customer the first impression about the engineering and build quality of the vehicle. Door hinge inclination and hinge contact flushness tolerance are the major design parameters affecting this performance. Although these are an important design parameter, the precise quantification of the effect of these design parameters on door performance under abuse loading has remained somewhat elusive. Traditionally, this assessment was done using physical testing, thumb rules and best practices rather than using computer aided techniques. However with the automotive industry moving towards higher durability targets, reduced product cycle time and lower design costs, the need for virtual simulation has increased. The scope of this paper includes, study of load distribution on the top and bottom hinge pair of the door under over opening abuse load due to hinge contact flushness tolerance and the effect of change in door axis inclination on the door performance under door sag abuse loading. The Finite Element Modelling (FEM) techniques, boundary conditions and the interpretation of the changes in design parameters on the door assembly performance under sag and over opening loading are detailed in the subsequent discussion. |
Magna’s New Ultralight Door - A Comparative LCA Study of the Lightweight Design as per ISO 14040/44 LCA Standards and CSA Group LCA Guidance Document for Auto Parts | In response to ever more challenging global fuel economy and environmental regulations, automakers will rely on lightweighting to continue to meet the established goals. As “bolt-on” subassemblies, closure panels provide a unique opportunity to tailor the vehicle mass to achieve local environmental compliance relative to a global vehicle platform while maintaining equivalent functionality and safety performance. This paper is aimed at communicating the results of a life cycle assessment (LCA) study which compares the lightweight auto parts of the new Magna’s Ultralight Door design to the conventional auto parts of the baseline 2016 MY Chrysler 200C 6 cyl, 3.6 L, automatic 9-spd, an ICE vehicle (gasoline fueled) built and driven for 250,000 km in North America (NA) [1]. Magna International Inc. (Magna), in cooperation with the United States Department of Energy (U.S. DOE) and partners FCA US LLC (FCA US) and Grupo Antolin, developed a new ultralight door architecture in 2017 that achieved around 40% overall mass reduction compared to the baseline door. Magna’s Ultralight door LCA study is conducted in accordance with International Organization for Standardization (ISO) standards 14040/44 and follow the specific rules and guidance provided in the CSA Group 2014 LCA Guidance document for auto parts [2, 3, 4]. |
Optimal Study on the TL of Automotive Door Sealing System Based on the Interior Speech Intelligibility | Wind noise becomes the foremost noise source when a car runs at high speeds. High frequency characteristics of wind noise source and effective performance of seal rubbers for insulating leakage noise make research on the Transmission Loss (TL) of automotive door sealing systems significant. The improvement of TL of automotive door sealing system could effectively decrease the interior noise due to wind noise for vehicles at high speeds. In this study, compression simulation of seal rubbers for an automotive door is performed through a Finite Element (FE) tool firstly. Compressed geometries of the seal rubbers are obtained. Then, based on the final compressed geometries and pre-stress modes of the automotive door seal rubbers, the TL of the whole door sealing system is acquired by hybrid Finite Element - Statistic Energy Analysis (FE-SEA) method. The fluctuating surface pressure on a car body was captured by a Computational Fluid Dynamics (CFD) tool. The wind noise source is obtained by the Corcos model and the Boundary Element Method (BEM). A full vehicle SEA model is built to predict the interior sound pressure level. The TL of the automotive door sealing system is included in the full vehicle SEA model. After the SPL in the car is obtained by SEA simulation, the Articulation Index (AI) is calculated. Finally, the TL of the automotive door sealing system is optimized by orthogonal design of experiment based on AI. This integrated approach can be used to optimize TLs of automotive door sealing systems. |
Research on Stick & Sprag-Slip Phenomenon of Door Waist Belts | The squeak noise generated during the moving of the door glass has a influence on the performance of vehicles felt by the consumer. In order to improve the noise, it is necessary to understand the principle of a friction vibration. In this paper, it is confirmed that the principle on the waist belt is most closely related to stick-slip and sprag-slip among various vibration characteristics. Stick-slip is expressed by energy accumulation and divergence due to difference in static and dynamic friction coefficient. Sprag-slip define instability of geometric structure due to angle of lips on the belt. In this paper, the physical model and the energy equation are established for the above two phenomena. Stick-slip can be solved by decreasing the difference of the static and dynamic friction coefficient. Sprag-slip is caused by the ratio of compressive and shear stiffness of the lips. The belt uses flocking to ensure durability, not coating. Therefore five factors that can be considered in the production of flocking are selected such as thickness. This study introduces an approach to improve the noise using DFSS. To predict the sprag-slip, the lips was modeled by a spring-damper system, and the stiffness value could be derived by applying shear deformation after compression load. The shapes of the lips were designed with 18 cases and the guide for the optimum was provided. It is found that positional deviation occurs due to the equilibrium of forces rather than merely by the tolerance when the glass of the vehicles can be moved from 0 to 2.6 mm. The optimization was confirmed that no squeak noise occurred even under the condition of 3 mm. |
Bumper on Striker: Improve Customer Perception Regarding Door Closing Sound Quality | Did you had opportunity to hear any unpleasant noise when closing some vehicle door? In some cases reminds a metallic touch condition, in other cases reminds several components loose inside the door. The fact is that this kind of noise is definitely unpleasant to the human ears. The good news is that this undesirable condition can be solved easily through of add a soft bumper in the striker; however, needs to pay attention in the material properties and tolerance stack-up conditions to avoid generate side effect, like as high door closing efforts, break parts, lose parts, etc. |
Drivmatic® Automatic Fastening System with Single Robot Positioner | The focus of this technical paper is a unique automatic fastening system configuration for loading, positioning & unloading pre-tacked door assemblies within a static C-Frame Drivmatic® fastening machine using an off-the-shelf, high accuracy Fanuc robot. In 2011, PMC was awarded a significant contract for supplying commercial OEM aircraft doors and recognized automation was the most feasible approach for fastening each door assembly. At the time of contract award, PMC was an established aero structure supplier with significant automation capability for machining high tolerance parts & assemblies and manual fastening resources to support many different OEM programs however PMC did not have automatic fastening experience or capability. In support of this new Tier-2 contract, PMC reached out to Gemcor to propose a collaborative robot solution for automatically fastening 5 different door assemblies that were historically fastened using a semi-automatic configuration. Demand for quality rivet & Hi-lok installation, preventing rework, fast throughput and avoiding a foundation paved the way for Gemcor to develop a lean approach for fastening some of the most challenging and labor intensive aero structure assemblies. |
Ultra-Light Weight Automotive Door: Design and Validation | An Ultra-Light Door (ULD) has been developed that is 40% lighter than a baseline 2016 mid-size vehicle’s driver side door. The ULD scope encompasses the entire door, including the door-in-white (DIW), interior trim, glazing, hardware, wiring, etc. To achieve such a substantial mass reduction while still meeting the baseline vehicle’s performance metrics (including safety, durability, NVH, appearance, etc.) at a minimal cost increase, the door design relies on a comprehensive full system approach that includes a unique architecture in addition to lightweight materials and components. This paper details the ULD design concept, simulated performance results, the current status of vehicle level validation, and comparisons between component level CAE predicted performance and physical test results. |
Numerical Simulation Research on Pressure during Door Closure of Commercial Vehicle | The magnitude of door closing force is important in vehicle NVH characters, and in most case, it is not fully studied by computer aided engineering (CAE) in an early developing stage. The research took a heavy-duty truck as the study object and used Computational Fluid Dynamic (CFD) method with dynamic mesh to analyze the flow field of the cabin during door closing process. The change trend of pressure with time was obtained, and the influence of different factors was studied. The experiments were conducted to verify the results. Results show that the velocity of closing door and the size of relief holes have a significant influence on cabin interior pressure, and greater velocity leads to larger the pressure in cabin. The initial angle of the door affects interior pressure less comparing with the velocity of closing door. The interior pressure could be reduced effectively with the method of decreasing the velocity of closing door and increasing the size of relief holes. |
Using Air Walls for the Reduction of Open-Door Heat Losses in Buses | A vital contribution for the development of an environmental friendly society is improved energy efficiency in public transport systems. Increased electrification of these systems is essential to achieve the high objectives stated. Since the operating range of an electrical vehicle is heavily influenced of the available energy, which primarily is used for propulsion and thermal passenger comfort, all heat losses in the vehicle systems must be minimized. Especially for urban buses, the unwanted heat losses through open doors while passengers are boarding, have to be controlled. These energy fluxes are due to the large temperature gradients generated between in- and outdoor conditions and to install air-walls in the door opening areas have turned out to be a promising technical solution. Based on air-wall technologies used for climate control in buildings, this paper presents an experimental investigation on the reduction of heat losses in the door opening of urban buses. Devices for creating the air-wall were located on top of the door opening of an articulated bus of Dresden public transport service DVB AG. Measurements of temperatures were conducted using distributed NTC-sensors. An extensive measuring program was performed and it was found that the air walls had a significant influence on the energy exchange process. On a short door opening time the energy losses increased, while for longer door opening times major reduction on the energy losses were achieved. |
AUTOMOTIVE DOOR CLOSING EFFORTS STUDY | The door is the first system to interact with the customer, allowing the entrance into the vehicle, so it has been given great importance to its performance in all requirements. The automotive door related phenomena studies increased in the past years, once the customer and the market itself have changed their quality standards. The door closing effort is considered a quality issue by the customer, cases it is too high it contributes to quality decrease, based on ergonomics study, each OEM specifies to each vehicle an acceptable value for the closing effort. There is software that uses the finite element method and specific calculation plans for the door closing effort at project phase, but it is necessary lots of data usually not available for the engineer at concept phases. This study's objective is to measure each component contribution in door closing effort with the use of a simplified plan in order to help the product engineer in the door concept phases. Also to help on decisions related to the door Design concept early in the development, minimizing the impacts from possible required changes in later project phases. From a simplified model this plan was made and the output of it was compared to simulations of complex models (CAE). The proposed model has acceptable error, when compared to CAE models, showing the simplifications made were made using criteria in order to impact the less possible in the door closing effort value. |
A Case Study: Application of Analytical and Numerical Techniques to Squeak and Rattle Analysis of a Door Assembly | Squeak and rattle (S&R) problems in body structure and trim parts have become serious issues for automakers because of their influence on the initial quality perception of consumers. In this study, various CAE and experimental methods developed by Hyundai Motors for squeak and rattle analysis of door systems are reported. Friction-induced vibration and noise generation mechanisms of a door system are studied by an intelligent combination of experimental and numerical methods. It is shown that the effect of degradation of plastics used in door trims can be estimated by a numerical model using the properties obtained experimentally. Effects of changes in material properties such as Young's modulus and loss factor due to the material degradation as well as statistical variations are predicted for several door system configurations. As a new concept, the rattle and squeak index is proposed, which can be used to guide the design. The predicted S&R of the door system from the CAE process were compared with experimental results. Practical applications of the developed process and possible future directions of CAE based S&R analysis are discussed. |
A CAE Study on Side Doors Inner Panel Deflection under Glass Stall Up Forces | Not only well-functioning, but also the way operating everyday items "feel", gauges costumer perception of an automobile robustness. To prevent costumer dissatisfaction with door trim panel movement when operating power windows, deflections must be kept small. Deflections of inner panel are seen through trim panel and are responsible for giving a flimsy idea of the door. In this paper, inner panel movement for a fully stamped door in full glass stall up position is analyzed. Through CAE analyses, inner panel behavior was compared, considering different types of reinforcement for belt region. |
Comparative Dynamic Analysis of Sliding Door Based on LS-Dyna and ADAMS | Nowadays, the design and development of the sliding door has been gained great attention for its easy egress and ingress. However, most studies on the kinematic and dynamic characteristics of sliding doors were based on the commercial code ADAMS, while the accuracy of flexibility in modal synthesis method and the ability of complex contact condition may not be guaranteed. Thus, a new dynamic analysis method by using the commercial code LS-Dyna was proposed in this paper to take into account the complex deformation and boundary conditions based on the finite element model. The impact force obtained from the Ls-dyna was compared with that from ADAMS when their monitoring points speed and closing time maintained the same during the sliding process. The impact force between the rollers and the guides was employed as evaluation criterion for different methods because of its effect on the roller wear and the moving smoothness in the sliding process. To validate the results, the impact force was measured by using the strain gauges and optical fibers measure. It turned out that the impact force from LS-Dyna agrees better with the experimental test than that from ADAMS. LS-dyna outperforms ADAMS, in terms of modeling method, dynamic analysis theory and boundary condition. In addition, the dynamic analysis based on finite element method in LS-Dyna environment can simulate the structural deformation and the motion space coupling boundary condition during the sliding process of door better. |
Re-design of Power Sliding Door Pulley System | The power sliding door system(PSD) is being equipped in the MPV(Multi-Purpose Vehicle/minivans) vehicle for convenience in the door operation. This study will focus on package space optimization for interior design and overall vehicle packaging for the vehicles equipped with PSD. To optimize the package, investigation for PSD's structure need to be done and the examples of other vehicle maker will be investigated and compared. The study that considers performance and package requirements resulted in a unique PSD design. And finally, this study will show the result vehicle in which the optimized mechanism is applied. |
Rivet and Bolt Injector with Bomb Bay Ejection Doors | Electroimpact's newest riveting machine features a track-style injector with Bomb Bay Ejection Doors. The Bomb Bay Ejection Doors are a robust way to eject fasteners from track style injector. Track style injectors are commonly used by Electroimpact and others in the industry. Using the Bomb Bay Doors for fastener ejection consists of opening the tracks allowing very solid clearing of an injector when ejecting a fastener translating to a more reliable fastener delivery system. Examples of when fastener ejection is needed are when a fastener is sent backwards, when there are two in the tube, or when a machine operator stops or resets the machine during a fastening cycle. This method allows fasteners to be cleared in nearly every situation when ejecting a fastener is required. Additional feature of Electroimpact's new injection system is integrated anvil tool change. Anvils with fingers are parked on each Injector and an indexing system automatically changes tools for different fastener diameter. Fundamentally, this track-style Injector has only one moving part, the Pusher, used in every fastening cycle. With the Bomb Bay Door ejection system and the integrated automatic tool change, this injection system is very flexible, and is likely one of the fastest in the industry with injection times of under a second. In addition to speed, the new eject system is a robust way to recover from common errors, adding to machine reliability. Overall the new injection system featured on Electroimpact's new riveting machines is a fast, flexible, and robust new system for fastener delivery. |
Challenges Associated with a Complex Compound Curvature Passenger Doors | This study investigates challenges associated with integrating a passenger (PAX) door on complex compound curvature (CCC) fuselages. Aerospace companies are investigating concepts that no-longer have constant cross-section (CS) fuselages. The PAX door is based on a generic semi-plug door for a long range business jet (BJ). This study investigates limitations of locating the door by varying the transition zone angle. A parametric CATIA tool, coupled with the use of finite element model (FEM) results can highlight key drivers in the design and location of PAX doors, creating a first-draft structural layout. The associated impact on the design and structural architecture for a fold down PAX door with integrated stairs is discussed. The impact of CCCs on the PAX door design is investigated with consideration to location, kinematics and function of the door. Design requirements, when coupled with stress analysis to simulate pressurization effect of the load applied to the stops, can create a powerful tool. Combining the architectural layout, design requirements and top-level stress analysis can be used to define limit curves and understand key design drivers that impact the door position, with reference to weight, design and human factor constraints. The design conclusions to-date suggest for a transition angle above 5 degrees, the structure is too complex to use a traditional frame and lintel design and will be an interesting case for bird impact. Below 5 degrees is the limit for conventional door and kinematic designs in-line with frames. |
InCar - Advanced Door Design | The ThyssenKrupp InCar Project is a comprehensive R&D development that gives automotive manufacturers modular solution kits for body, chassis and powertrain applications. The solution kits developed within this project offer weight reduction, cost savings or improved functionality. This paper will focus on the two front door solutions developed within the InCar project. The first door solution, called the Lightweight Door, achieved a 13% weight reduction. This door features a 4-piece tailored blank inner panel and a sandwich material outer panel. The second door solution, called the Advanced Door, is a completely new and innovative door architecture that uses a 2-piece tailored blank mid panel and ultra thin Dual Phase 500 outer panel to achieve an 11% weight reduction. Prototypes were manufactured and tested for both door solutions. This paper will provide a detailed description of everything related to the development of these door solutions, including manufacturing and assembly processes, performance, materials, and cost estimation. |
Study of the Sliding Door Shaking Problem and Optimization Based on the Application of Euler’s Spiral | This study focuses on the sudden shaking phenomenon of a sliding door passing through a corner. This phenomenon requires attention because shaking during movement can lead to a harsh operation feeling and a short service life. An experiment based on a test setup was conducted, and the sudden change in the acceleration of a sliding door panel was measured. Based on multi-body dynamics (MBD) analysis and a rigid-flexible coupled model of the sliding door system, the cause of the sudden shaking was determined to be the discontinuous curvature of the middle rail trajectory. A transition curve was proposed as the solution for the discontinuous curvature, and Euler’s spiral was applied in the redesign of the middle rail trajectory. Verified by simulations, the results exhibit considerable improvement in sliding door movement stability, with large reductions in the maximum center of mass (CM) acceleration and guide roller impact force. |
Application Study of Blind Spot Monitoring System Realized by Monocular Camera with CNN Depth Cues Extraction Approach | The image from monocular camera is processed to detect depth information of the obstacles viewed by the rearview cameras of vehicle door side. The depth information recognized from a single, two-dimensional image data can be used for the purpose of blind spot area detection. Blind spot detection is contributing to enhance the vehicle safety in scenarios such as lane-change and overtaking driving. In this article the depth cue information is inferred from the feature comparison between two image blocks selected within a single image. Convolutional neural network model trained by deep learning process with good enough accuracy is applied to distinguish if an obstacle is far or near for a specified threshold in the vehicle blind spot area. The application study results are demonstrated by the offline calculations with real traffic image data. |
Utilizing Weathering Effect to Understand Squeak Risk on Material Ageing | Squeak and rattle concerns accounts for approximately 10% of overall vehicle Things Gone Wrong (TGW) and are major quality concern for automotive OEM’s. Objectionable door noises such as squeak and rattle are among the top 10 IQS concerns under any OEM nameplate. Customers perceive Squeak and rattle noises inside a cabin as a major negative indicator of vehicle build quality and durability. Door squeak and rattle issues not only affects customer satisfaction index, but also increase warranty cost to OEM significantly. Especially, issues related to door, irritate customers due to material incompatibilities. Squeaks are friction-induced noises generated by stick-slip phenomenon between interfacing surfaces. Several factors, such as material property, friction coefficient, relative velocity, temperature, and humidity, are involved in squeak noise causes. For example, door armrest leather is exposed longer to sunlight and when customer places his hand on the armrest, an annoying squeak noise is generated due to permanent or temporary weathering effect. In this study, an experimental work is conducted to investigate squeak performance of door trim materials against weather ageing effect. As per the standard SAE-J2412, one thousand five hundred hours of polymer weathering test which is considered equivalent to 5 years of product life were performed to door trim material samples. Material compatibility test were performed on door trim samples at different time intervals of 0, 250, 500,750, 1000& 1500 hrs to evaluate its squeak risk behavior. On basis of RPN results, it was found that some material combination failed at 500 and 750 hrs highlighting squeak risk due to weathering effect. This paper introduces a new DVP, where a process can be established for material selection and avoid customer irritants and improve the perceived quality not only for a new vehicle but even after mileage degradation. |
Door Seal Behavior Prediction and Enhancement in Performance Using Digital Simulation | Automotive door seal has an important function which is used extensively where interior of the vehicle is sealed from the environment. Problem with door seal system design will cause water leakage, wind noise, hard opening or closing of doors, gap and flushness issue which impair customer’s satisfaction of the vehicle. Moreover, improper design of seal can lead to difficulty in installation of door seal on body panel. The design prudence and manufacturing process are important aspect for the functionality and performance of sealing system. However, the door sealing system involves many design and manufacturing variables. At the early design stage, it is difficult to quantify the effect of each of the multiple design variables. As there are no physical prototypes during rubber profile beading-out stages, engineers need to carry out non-linear numerical simulations that involve complex phenomena as well as static and dynamic loads for door seal. This paper presents a digital simulation design tool based on FEM, basic governing laws and incompressibility constraints. Door seal was analyzed for compression load deflection (CLD) behavior using nonlinear finite element analysis in MSC Marc Mentat™. The analysis results provided some major parameters, such as seal deformation, contact pressure and contact length of seal, which would influence the functionality and performance of the door sealing system. The analysis results have been compared with available test data, and very good correlation was obtained. This analysis also evaluated the influence of manufacturing deviations. This analysis method developed into a tool that is capable of predicting water leakage, wind noise and hard to open/close problems caused by either product design or manufacturing process. |
Sink Butt Welding for 120 Degree Door Frame Design | This paper deals with vehicle door 120-degree joint rust issue and water leak faced in most of SUV cars. Generally based on vehicle segment its styling curves and exterior design are defined. A Sedan or Hatchback is provided with curves to show its fluidic design but a SUV is provided with Straight lines to show its aggressive look. In existing condition door frame Joint has sharp joints where weld bead is added to prevent rust in joint area, but still improper seating of weather strip on weld bead cause water leak. Door’s A Pillar Frame and Horizontal Frame match at 120 degree joint edges are chamfered straight to match perfectly. Weld bead runs over the matching profile to join it. But weld bead project over the Frame surface and affects weather strip seating & results in poor sealing. Adhesive added for better sealing also follows the same path on bead and create a path way for water entry. Thus in long run this water stagnates and cause chronic rust issues in frame. This in turn results in high claim cost within warranty period. It is serious issue which should be addressed. This paper investigates deeply the process of eradicating the rust issue and water leak issue simultaneously. Edges of frame are provided with forming at 120 Joint matching areas. So that weld bead gets sink into shallow depth without projecting out from the surface. This flattened profile of weld bead on frame surface results in perfect sealing of weather strip. This is how sink weld prevents rust and arrest water entry. |
Squeak Noise Prediction of a Door Trim Panel Using Harmonic Balance Method | Squeak and rattle noise in a vehicle’s interior is perceived as an annoying sound by customers. Since persistent noise (e.g. engine, wind or drive train noise) has been reduced continuously during the last decades, the elimination of sounds, which have their origin in the vehicle’s interior components, is getting more important. Therefore, noise prediction based on simulation models is useful, since design changes can be realized at lower costs in early virtual development phases. For this task, linear simulation methods are state of the art for the identification of noise risk, but in general without knowing if a sound is audible or not. First approaches have been developed based on the Harmonic Balance Method to predict squeak noise and assess their audibility. This paper presents vibroacoustic measurements at a door trim panel for squeaking and non-squeaking configurations. Vibrations are excited harmonically by a force controlled low noise shaker. The system response is measured in a semi-anechoic chamber by acceleration sensors and audibility is assessed. Additionally, a 3D finite element model is built and the Harmonic Balance Method using a dry friction law is applied to predict the acoustic behavior. Finally, the simulation results are compared to the measurements. A good agreement between simulation and experiment can be observed. |
Development of a Thin-Wall Magnesium Automotive Door Inner Panel | Cast magnesium (Mg) door inner panels can provide a good combination of weight, functional, manufacturing, and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility, and relatively low strength versus steel. A project was supported by the US Department of Energy to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, Mg inner panel. This development project is the first of its kind within North America. The 2.0 mm Mg design, through casting process enablers, has satisfactorily met all stiffness and side-impact requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies. The performance of the Mg design has been demonstrated through component and vehicle tests. This article is an updated publication of a previously published International Mg Association (IMA) proceedings paper [1] (with agreement from the Association). |
Damping out booming noise | NVH improvement techniques are gaining traction with the goal to improve the quality perception of off-highway equipment performance and operator comfort. As NVH gains importance in the quality of off-highway machine performance and operator comfort, it is essential to understand every aspect of the machine noise and its annoyance effect on the operator, then reduce the noise to a level that does not affect comfort and performance. Booming noise-a low-frequency NVH phenomenon below 200 Hz often described as a continuous bass drum roll, distant thunder sound, or a deep resonant sound like an explosion-is a major concern in off-highway machines. The booming noise in off-highway machines can be caused by a combination of factors: the low natural frequencies and damping of the large panels of machine cabs; the low acoustic modes of the cab cavity; low-frequency excitation into the cab from machine noise sources such as engine, exhaust, cooling fan, etc.; and low frequency excitation to the machines from machine work tools and ground interaction inputs (tire lug, road profile, etc.). |
Recent Advances in Powertrain Sound Quality Hardware Tuning Devices and Perspectives on Future Advances | Over the past decade there have been significant advances made in the technology used to engineer Powertrain Sound Quality into automobiles. These have included exhaust system technologies incorporating active and semi-active valves, intake system technologies involving passive and direct feedback devices, and technologies aimed at tuning the structure-borne content of vehicle interior sound. All of these technologies have been deployed to complement the traditional control of NVH issues through the enhancement of Powertrain Sound Quality. The aim of this paper is to provide an historical review of the recent industry-wide advances made in these technologies and to provide the author's perspective on what issues have been addressed and what opportunities have been delivered. The paper will offer the author's perspective on how these existing Sound Quality hardware tuning technologies have evolved, how they will continue to evolve, what new technologies are showing potential, and how they will have an increasingly significant contribution to make in the medium and long term future of Vehicle NVH and Sound Quality development. |
Applications of the Statistical Energy Analysis to Vibro-Acoustic Modeling of Vehicles | In recent years, SEA has been recognized as an important tool to model the vibro-acoustic behavior of vehicles in mid and high frequencies. Through SEA it is possible to develop vehicle models early in the design stage, reducing the risk of future noise problems and allowing the optimization of noise control treatments. Moreover, at the final design stages, a SEA model can be use to evaluate changes at the project, reducing costs with experiments. In a SEA model, the structure under study is divided in subsystems. The capacity of each subsystem of storekeeping, dissipating and transmitting energy is described by three parameters: modal density, loss factor and coupling loss factor. The noise and vibration sources are include in the model as power inputs to subsystem and, based on an equilibrium power balance, it is possible to calculate the energy of each subsystem. The results obtained by SEA models should be interpreted as average values in time, in the frequency band, in space and at an ensemble of random structures. In this work, the applications of SEA at the vibro-acoustic modeling of vehicles are discussed. The details that should be observed when defining the structural and acoustic subsystem are pointed out. The main methods for the determinations of the SEA parameters are introduced. Special emphasis is given to the calculation of the power inputs of the main noise and vibration sources in a vehicle. Finally, some practical applications of SEA at the automotive industry are presented and discussed. |
TREASURI: An Innovative Simulation Method for the Vibro-Acoustic Design of Passenger Compartments | 0 The accuracy of nowadays CAE tools for simulation of sound pressure level distributions in the passenger compartment of vehicles is not satisfactory because of the simplify models, especially with regard to the description of common passive acoustical treatments. This report describes the application of the TREASURI method on a complete vehicle, equipped with sound deadening treatment sound absorbing material sound insulation treatment and interior trim material (e.g. instrument panel, seats, center console). In order to validate the method, the simulation results were compared with the measurement results from the corresponding vehicle. The evaluation shows that the TREASURI approach yields considerable improvements in simulation accuracy up to 300 Hz compared to classical approaches [1]. This method now enables reliable predictions of acoustical influence on structural modifications and changes of the sound package. |
Visualization of Sound Field in Automobile Cabin using Sound Intensity Technique | For examining sound field in automobile cabin, it is important to visualize a noise source and it's behavior. This paper reports the results of visualized sound field using measurement data of sound intensity analysis. In general, it is difficult to obtain an appropriate result for source localization in reflective sound field where normal mode can be occurred with sound intensity analysis. We tried to distribute many receiving points and examined noise source localization in automobile cabin with this technique and found it effective. After the treatment of sound insulation, we found that measurement results reveals difference with and without countermeasure. |
Real-Time Pass-by Noise Source Identification Using A Beam-Forming Approach | Noise source identification is becoming a key issue in the dimensioning and troubleshooting steps of the design process. In the automotive industry, OEM's and suppliers need to assess the entire description of vehicle noise emission, both for interior comfort and exterior radiation concerns. The resolution of pass-by noise issues pose one of the most significant problems to vehicle designers. While many commercially available systems allow the evaluation of the overall noise emission at any speed and position during the test the task of identifying specific sources is still mainly performed using component masking. A new measurement technique has been developed using a microphone array (typically 2m × 2m with 64 transducers or more) and acoustic beamforming techniques that allows visual source identification at any point during the test. Typically, the entire side of a vehicle can be evaluated with one single measurement run. This paper describes the method employed and presents results obtained from a high-speed pass-by test on a minivan. |
Development of a Hybrid SEA Modeling Scheme for a Passenger Car | A hybrid SEA modeling scheme has been developed and applied to obtain an accurate SEA model for a passenger car. In this study, the detailed workflow associated with the hybrid SEA modeling scheme will be described. Each step in the workflow will be discussed in terms of the obtained data, the corresponding analysis and results. In those steps, several innovative methods for developing the hybrid SEA model will be presented. Finally, a road noise analysis will be performed using the hybrid SEA model to validate the SEA model for the passenger car. In order to demonstrate the accuracy of the model, the analysis results such as the sound pressure level of car interior will be compared with the measurements. |