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Viewing 211 to 28 of 28
2016-04-05
Technical Paper
2016-01-1398
Ahmet Turan
Abstract Optimization of a structure which is subjected to simultaneous multiple load cases starts with the investigation of worst possible load case combination. This is called conventional optimization approach, which can be considered impractical due to the excessive CPU times in the application of multiple load cases. This computational difficulty can be overcome by deploying singular value decomposition (SVD) to find the worst possible load case against which the structure should be optimized. To this end, the SVD based optimization approach to optimization of a structure subject to simultaneous multiple load cases is presented. Conventional Multiobjective optimization and SVD based Multi-objective optimization approaches are applied to a sample Commercial Truck Chassis Frame structure for durability vs. weight objectives. This will enable designer to select the optimum design parameters out of the calculated Pareto sets.
2016-04-05
Technical Paper
2016-01-1384
Mengshi Deng, Jian Lan
Abstract Glass lifter is a key part of automobile door system. Guide rail is the carrier of glass lifter, and it bears various load cases when glass lifer works. Mass, stiffness and natural frequencies are the factors that influence the performance of glass lifter. In order to design a lighter and reasonable glass lifter, topology optimization methods are studied in this paper. In a rope-wheel glass lifter, design domain is determined by the mechanical structure and working conditions. Firstly, the single target continuum structure topology optimization mathematic models of guide rail are built in this paper, and analysis of multi-stiffness topology optimization are carried out accordingly in which volume fraction is set as 0.4, 0.5 and 0.6. These models are based on SIMP (Solid Isotropic Material with Penalization) theory.
2016-04-05
Technical Paper
2016-01-1365
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
Abstract The overall automotive industry is moving toward first time right test which in turn needs first time right analysis. This is due to the enormous pressure of cost, mass, time to market and availability of prototype vehicles for testing. Use of finite element methods enables to upfront predict the system behavior in operating conditions and evaluation of structural strength. In vehicle product development process, hood slam durability evaluation is one of the important tests for body closure structure. Current work showcases an effort made for developing virtual hood slam test. The virtual model consists of BIW, hood, hinge joint, interface like CRFM (cooling-radiator-fan module) and latch mechanism with spring preload. Analysis performed with LSDyna solver. An impact loading is applied by converting potential energy to kinetic energy, mimicking the hood dropping from a specified height on the hood latch.
2016-04-05
Technical Paper
2016-01-1349
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
Abstract In the current scenario, the major thrust is to simulate the customer usage pattern and lab test using virtual simulation methods. Going ahead, prime importance will be to reduce the number of soft tool prototype for all tests which can be predicted in CAE. Automotive door slam test is significantly complex in terms of prediction through simulation. Current work focuses on simulating the slam event and deriving load histories at different mounting locations through dynamic analysis using LSDyna. These extracted load histories are applied to trimmed door Nastran model and modal transient analysis is performed to find the transient stress history. This approach has a significant advantage of less computation time and stress-convergence with Nastran for performing multiple design iterations compared to LSDyna. Good failure correlation is achieved with the test using this approach.
2016-04-05
Technical Paper
2016-01-1351
Simhachalam Bade
Abstract Aluminum alloys are widely used in the transportation because of their high strength-to-weight ratio and outstanding capability in absorbing energy. In this paper, performance of bumper with crash tubes using aluminum alloy AA7003 materials is compared with that of AA6061 and high strength steel (DP800) using numerical methods. Quasi-static test is simulated using the LS-DYNA implicit finite element program. Bumper and crash tubes are included in the finite element model. Symmetric Holes are provided in the crash tubes to initiate crushing. The energy absorbed by bumper and crash tubes are compared. Dynamic simulation is done using LS-Dyna explicit program. True stress-true plastic strain curves at different strain rates from the literature is used in the dynamic simulation of AA7003 material to study the strain rate effects on impact behavior of tubes. The impact mass is represented by RigidWall Planar Moving Force option in LSDYNA.
2016-04-05
Technical Paper
2016-01-1612
Francesco Mariani, Francesco Risi, Nicola Bartolini, Francesco Castellani, Lorenzo Scappaticci
Abstract Aerodynamics is one of the most important factors in the development of racing cars. At the speeds of formula cars reach the formula cars, the driver's neck can be subjected to stresses resulting from the aerodynamic forces acting on the helmet; developing an aerodynamic project that takes into account the comfort of the driver without affecting performance is certainly considered a challenging activity. The aim of the present work is to develop a low-pitching-momenthelmet for formula racing cars optimizing the shape and location, applying some aerodynamic appendices. This goal is pursued by adopting an approach based on both experimental and numerical activities. First, the aerodynamic configuration of an existing helmet was examined; through a testing campaign in the wind tunnel facilities of Perugia University, pressures acting on the helmet were scanned at various speeds and data about aerodynamic drag were collected.
2016-04-05
Technical Paper
2016-01-0246
Rupesh Sonu Kakade, Prashant Mer
Abstract Vehicle occupants, unlike building occupants, are exposed to continuously varying, non-uniform solar heat load. Automotive manufacturers use photovoltaic cells based solar sensor to measure intensity and direction of the direct-beam solar radiation. Use of the time of the day and the position - latitude and longitude - of a vehicle is also common to calculate direction of the direct-beam solar radiation. Two angles - azimuth and elevation - are used to completely define the direction of solar radiation with respect to the vehicle coordinate system. Although the use of solar sensor is common in today’s vehicles, the solar heat load on the occupants, because of their exposure to the direct-beam solar radiation remains the area of in-car subjective evaluation and tuning. Since the solar rays travel in parallel paths, application of the ray tracing method to determine solar insolation of the vehicle occupants is possible.
2016-04-05
Technical Paper
2016-01-0240
Ruobing Zhan, Gangfeng Tan, Bo Yang, Zhiwei Zhang, Tie Wang, Cenyi Liu, Xintong Wu, Yanjun Ren, Haobo Xu
Abstract The Organic Rankine Cycle System (ORC) is an effective means to use the solar energy. The system adopts the solar energy on the car roof as the heat source to make the ORC work and drive the thermoelectric air-conditioner. It can improve the entering comfort on the parking condition and the vehicle energy utilization efficiency. In this research, the system comprehensively applied the principle of sunshine concentration, heat collection and photo electricity. Then considering the working condition and performance features of ORC system, the car roof was designed to have a compact structure, through which the efficiency of the solar vehicle system could be improved. Firstly, the research analyzed the heat source temperature and the heat flux impact on the output power of the ORC system. After that, the performance of heat collection was identified according to the given thermoelectric air-condition’s power requirements.
2016-04-05
Technical Paper
2016-01-0391
Tanmay Sushant Santra, Vikas Kumar Agarwal, Mihir Bhambri
This paper depict the difference in the endurance factor of safety with usage of static and quasi static FE analysis and corrective measures take to solve the problem. The importance of the dynamic loading and subsequent effect of it on the multi axial fatigue analysis. Considering the modern trend prevailing among the vehicle manufacturers and specifically talking about two wheeler industry, it is clear that while the engine remains the same but the frame is changed to cater the market with new models to cut down on the development time. Initially the crankcase was designed for a double cradle frame where the crankcase was mounted on the frame. Later, the frame design was changed to single cradle where engine acts as a stress member link. This kind of arrangement makes the crankcase mountings participate in the chassis loads. Therefore, the crankcase mounting experiences road loads when the vehicle encounter the road irregularities.
2016-04-05
Journal Article
2016-01-0387
Yunkai Gao, Jingpeng Han, Jianguang Fang, Shihui Wang
Abstract A compiled method of the programmed load spectrum, which can simplify and accelerate the fatigue bench test of a car body, is proposed and its effectiveness is checked by the fatigue simulation. By using the multi-body dynamics model with a satisfactory accuracy, the virtual iteration is applied to cascade body loads from the wheel hubs. Based on the rain-flow counting method and statistics theory, the distributions of the body loads are analyzed, and then the programmed load spectrum is compiled and simplified. Through comparative study, the simulation results of random and programmed load spectrum are found to agree well with each other in terms of the damage distribution and fatigue life, which demonstrates the effectiveness of the presented method.
2016-04-05
Technical Paper
2016-01-0216
Ramanand Singh, Remesh Kuzhikkali, Nitesh Shet, Sekarapandian Natarajan, Govind Kizhedath, Murugan Arumugam
Fogging (i.e. condensation of water vapor) in headlamps in severe weather conditions present both a performance and potential safety concern for automotive companies. Conventional headlamps are based on incandescent bulbs. In recent times, LED lighting has increasingly become the norm. However, LED based headlamps are prone to higher levels of fogging because they inherently produce less heat than the conventional incandescent or halogen bulbs. A headlamp design must be able to dispose all the formed condensate/fog in a fixed time even under severe thermal conditions. It is of great importance for the car manufacturer to be able to simulate the risk of condensation early in the design stage with an eye on the overall cost reduction. The combined use of experimental studies and numerical modelling is important to optimize headlamp design and to produce high-performance headlamps.
2016-04-05
Technical Paper
2016-01-0208
Xuzhi Du, Zhigang Yang, Hua Zhou, Qiliang Li, Zheyan Jin
Abstract The effect of jet geometry on flow, heat transfer and defrosting characteristics was numerically investigated for elliptic and rectangular impinging jets on an automobile windshield. Initially, various turbulence models within the commercial computational fluid dynamics (CFD) package FLUENT were employed and validated for a single jet, and the results indicated that the impinging jet heat transfer was more accurately predicted by the SST k -ω turbulence model, which was then utilized for this study. The aspect ratios (AR) of elliptic and rectangular jets were respectively 0.5, 1.0, and 2.0, with jet-to-target spacing h/d=2, 4 and jet-to-jet spacing c/d=4, and all those situations were numerically analyzed with the same air mass flow and jet open area. It was observed that the heat transfer coefficient and defrosting performance of the inclined windshield were significantly affected by the shape of the jet, and the best results were obtained with the elliptic jet arrangements.
2016-04-05
Journal Article
2016-01-1395
Syed F. Haider, Zissimos Mourelatos
Abstract To improve fuel economy, there is a trend in automotive industry to use light weight, high strength materials. Automotive body structures are composed of several panels which must be downsized to reduce weight. Because this affects NVH (Noise, Vibration and Harshness) performance, engineers are challenged to recover the lost panel stiffness from down-gaging in order to improve the structure borne noise transmitted through the lightweight panels in the frequency range of 100-300 Hz where most of the booming and low medium frequency noise occurs. The loss in performance can be recovered by optimized panel geometry using beading or damping treatment. Topography optimization is a special class of shape optimization for changing sheet metal shapes by introducing beads. A large number of design variables can be handled and the process is easy to setup in commercial codes. However, optimization methods are computationally intensive because of repeated full-order analyses.
2016-04-05
Technical Paper
2016-01-1380
S. Khodaygan, Amir Ghasemali, Hamed Afrasiab
Abstract One of the most important characteristics of industrial products, especially mechanical set-ups, is considering the tolerances of production and assembly of these set-ups, which directly influences the products’ operations. In sheet metal structures, due to the high flexibility of the sheets, the errors appeared while assembly will be as highly influential as the errors due to the production tolerance of the sheets. As a result, having a comprehensive model which could analyze the assembly process of these structures and also clarifies the relation between the tolerance of the parts and the ultimate changes of the set-up will be of considerable importance. During the assembly process, the contact effect between the components is inevitable. If such effect is not considered, the contact surfaces will permeate. The purpose of this paper is to present a method to analyze the tolerance of flexible sheet structures, considering the contact effect between surfaces.
2016-04-05
Technical Paper
2016-01-0434
Roshan N. Mahadule, Jaideep Singh Chavan
Abstract 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.
2016-04-05
Technical Paper
2016-01-1473
Orion P. Keifer, Bradley Reckamp, Charles Moody, Anthony Timpanaro
Abstract Evaluation of the severity of low speed motor vehicle crashes has been the subject of significant research for more than 25 years. These crashes typically result in little if any damage to the vehicles involved and therefore the ability to determine the threshold of damage would be very useful in analysis of such cases. One such threshold, which has been used by accident reconstructionists, is the manufacturer’s published bumper rating in compliance with Federal Motor Vehicle Safety Standards (FMVSS) for vehicle bumpers. The rationale is that if there is any damage to the bumper system of the vehicle in question, the impact must have had a severity greater than the rated bumper speed. This paper examines the FMVSS bumper standards upon which the published bumper ratings are reportedly in compliance, historical low speed testing damage results, and engineering considerations of bumper damage in low speed impacts.
2016-04-05
Technical Paper
2016-01-0217
Somnath Sen, Mayur Selokar, Diwakar Nisad, Kamal Kishore
Abstract Adequate visibility through the vehicle windshield over the entire driving period is of paramount practical significance. Thin water film (fog) that forms on the windshield mainly during the winter season would reduce and disturb the driver’s visibility. This water film originates from condensing water vapor on inside surface of the windshield due to low outside temperatures. Primary source of this vapor is the passenger’s breath, which condenses on the windshield. Hot and dry air which impinges at certain velocity and angle relative to the windshield helps to remove the thin water film (defogging) and hence improves driver’s visibility. Hence a well-designed demisting device will help to eliminate this fog layer within very short span of time and brings an accepted level of visibility. An attempt is made here to design and develop a demisting device for a commercial vehicle with the help of numerical and analytical approach and later on validated with experimental results.
2016-04-05
Journal Article
2016-01-1334
Christopher Flegel, Parth Bhivate, Liang Li, Yash Mathur, Sanket Phalgaonkar, Mark Benton, Prasanth Muralidharan, Johnell Brooks, Srikanth Pilla, Paul Venhovens, David Lewis, Garrett DeBry, Craig Payne
Abstract The Deep Orange framework is an integral part of the graduate automotive engineering education at Clemson University International Center for Automotive Research (CU-ICAR). The initiative was developed to immerse students into the world of an OEM. For the 6th generation of Deep Orange, the goal was to develop an urban utility/activity vehicle for the year 2020. The objective of this paper is to describe the development of a multimaterial lightweight Body-in-White (BiW) structure to support an all-electric powertrain combined with an interior package that maximizes volume to enable a variety of interior configurations and activities for Generation Z users. AutoPacific data were first examined to define personas on the basis of their demographics and psychographics.
2016-04-05
Journal Article
2016-01-1338
Syed F. Haider, Zissimos Mourelatos
Abstract Weight reduction is very important in automotive design because of stringent demand on fuel economy. Structural optimization of dynamic systems using finite element (FE) analysis plays an important role in reducing weight while simultaneously delivering a product that meets all functional requirements for durability, crash and NVH. With advancing computer technology, the demand for solving large FE models has grown. Optimization is however costly due to repeated full-order analyses. Reanalysis methods can be used in structural vibrations to reduce the analysis cost from repeated eigenvalue analyses for both deterministic and probabilistic problems. Several reanalysis techniques have been introduced over the years including Parametric Reduced Order Modeling (PROM), Combined Approximations (CA) and the Epsilon algorithm, among others.
2016-04-05
Journal Article
2016-01-1409
J. Christopher Watson, Gennady Dumnov, Alexander Muslaev, Andrey Ivanov, Svetlana Shtilkind
Abstract Condensation occurrence in automotive headlights can be detrimental to consumer acceptance of a product. This paper describes a technique for transient numerical simulation of liquid film formation on surfaces during lighting thermal analysis performed using Computational Fluid Dynamics (CFD), including how the film’s properties influence the thermal solution. The numerical technique presented accounts for the change in the film thermal state and thickness due to heat exchange with external fluid flow and solid bodies, surface evaporation/condensation, melting/crystallization within the film volume, and its motion due to gravity and friction forces from the surrounding airflow. Additionally, accurate modeling of radiation effects is critical for lighting applications, including the attendant influence on the thermal distribution of the solids that may have surfaces subject to condensation.
2016-04-05
Journal Article
2016-01-1407
Sama Hussein, Benjamin Hamilton, O. Remus Tutunea-Fatan, Evgueni Bordatchev
Abstract Retroreflective (RR) optical elements play a critical role in signaling, safety, and aesthetic/styling functionality of automotive lighting. The commonly-used inverted corner cube (ICC) RR structures with hexagonal aperture have several critical limitations that are primarily rooted in their manufacturing technique that involves complex assemblies/shapes of hexagonal pins and electroforms, particularly in case of freeform surfaces. This study introduces a novel RR micro-optical structure, namely: right triangular prism (RTP). The geometric model underlying this new geometry is defined as the intersection between a cube and a plane placed in a particular relative orientation with respect to each other. Following this, non-sequential optical simulation studies were performed analyzing the effect of incident light orientation.
2016-04-05
Journal Article
2016-01-1401
Thomas M. Cleary, Timothy Huten, Daniel Strong, Chester S. Walawender
Abstract The use of lightweight materials to produce automotive glazing is being pursued by vehicle manufacturers in an effort to improve fuel economy. As glazing’s become thinner, reduced rigidity means that the critical flaw size needed to create fracture becomes much smaller due to increased strain under load or impact. This paper documents experiments focused on the impact performance of several alternative thin laminate constructions under consideration for windshield applications (including conventional annealed soda-lime glass as well as laminates utilizing chemically strengthened glass), for the purpose of identifying new and unique failure modes that result from thickness reduction. Regulatory impact tests and experiments that focused on functional performance of laminates were conducted. Given the increased sensitivity to flaw size for thin laminates, controlled surface damage was introduced to parts prior to conducting the functional performance tests.
2016-04-05
Journal Article
2016-01-1595
Haibo Wu, Jiangbin Zhou, Qian Chen, Gongwen Liu, Chaoqun Qian
Abstract In this paper we present the work which was done at Shanghai-VW for using computational aero-acoustic (CAA) simulation in the vehicle development process to assess and improve the buffeting behavior of a vehicle when the rear side window is open. In the first step, a methodology was established and validated against wind tunnel tests using a Sedan. The methodology consists of a calibration of the CAA model to represent the properties of the cabin interior of the real car in terms of damping, wall compliance and leakage followed by CAA simulations of the full vehicle at different wind speeds to obtain the transient flow field around the exterior shape and inside the passenger compartment. The interior noise spectra are directly calculated from the transient pressure inside the cabin.
2016-02-01
Technical Paper
2016-28-0174
Pankaj Kumar Singh, Naman Taneja, Alok Nath Sharma, Adarsh Gaurav
Abstract In today’s fast moving vehicle scenario, road safety is of utmost importance. Many people have lost their lives while travelling, due to a road accident. So we should mitigate such accidents if we wish to travel safely. To cater this cause, we propose an adaptive steering controlled headlight setup. The system can be adopted in any type of four wheel vehicles/trucks or trailers etc. without being an economic burden on the end user. The notion of steering controlled headlight is not new, but its adaptability according to the steering turning angle is its novel part. A lot of companies have developed technologies that incorporate turn able headlight to better illuminate the path, but these technologies are quite expensive and continue to be distant from the majority of car owners. So we felt the need of developing a mechanism that incorporates few simple components like gears, linkages etc. and can be readily fitted onto any steering column without much of a design variations.
2016-02-01
Technical Paper
2016-28-0198
Joydeep Chatterjee, Harveen Talwar, Srishti Garg
Abstract In a typical passenger vehicle, there can be different types of noises generated which are broadly categorized as Interior Noise and Exterior Noise. The interior noise sources can be further classified into noises which can be Structure Borne or Air Borne. One of the major sources of both structure borne and airborne noise generation is the powertrain of the vehicle. The structure-borne noise and vibrations generated from the powertrain is usually transferred to the vehicle body through its attachment points to the body and the powertrain driveline. These induced body vibrations can sometimes cause the acoustic cavity of the passenger cabin to go into resonance which results in an annoying and disturbing noise for the passengers, called Booming Noise. Very often, one or more than one vehicle body panels show a dominant contribution in inducing this acoustic cavity resonance.
2016-02-01
Technical Paper
2016-28-0197
Nithin Alex John, Mona Sherki, Sanjay A Patil
Abstract New generation automobiles are equipped with power windows which eases the passenger’s effort in moving the vehicle windows up and down. Many of them are stuffed with advanced features like automatic up/down option for ensuring functionality with a single press of the switch. Even though it adds comfort to driver & passenger, inadvertent use of power window can be fatal if a person’s body part gets trapped inside. An effective solution for this problem is anti-pinch mechanism, which releases the object safely just when it gets trapped. It detects the object trapped and immediately moves the window down so that trapped object will get released easily. The anti-pinch algorithm used in this project is based on the “Method of Monitoring Movable Element”, method monitor traveling distance of a power window pane. In order to achieve this different from conventional techniques we are using Ultrasonic sensor.
2016-02-01
Technical Paper
2016-28-0210
Abhishek Sinha, Kamlesh Yadav, Rajdeep Singh Khurana
Abstract The biggest challenge in vehicle BIW design today is to make a light, cost effective and energy absorbing structure. With the increasing competition as well as increasing customer awareness, today’s vehicle has to satisfy several aesthetic and functional requirements besides the mandatory regulatory requirements. While working on global platform, it is challenging to comply with both pedestrian protection and low speed bumper impact (ECE-R42) and at the same time meeting the styling intent of reducing the front overhang. Pedestrian lower leg compliance demands space between bumper member and bumper, a condition that reduces the space available for energy absorption during low speed impact (ECE-R42). Therefore, reduction in front overhang poses a problem in meeting both the requirements with limited space.
2016-02-01
Technical Paper
2016-28-0242
Ashwin Vaidyanathan, Aono Noriaki
Abstract This paper reinforces the importance of correlation between CAE Analysis of CAB Bridge and Vehicle test data. CAB Bridge is a structural assembly, bolted to the Frame of a Truck. The initial objective of the study was to evaluate the influence of particular design modification on CAB Bridge. To perform CAE calculations, two different iterations of Boundary & loading conditions, were established and executed using CATIA V5. During Post processing of CAE results, detailed data analysis and interpretation were performed. The results of CAE Analysis and Vehicle test data were compared, to identify the iteration that correlated better with Vehicle test data. The data analysis and interpretation guided in finding key observations and concluding that the Torsion case as the most important loading condition.
2016-02-01
Technical Paper
2016-28-0250
Kamlesh Yadav, Ruhi Thakur
Abstract Hood is the closure provided in the frontal portion of the vehicle for covering the engine room. Any component disposed in the frontal portion of the vehicle becomes important because of aesthetic as well as regulatory requirements. Introduction of new regulations like pedestrian protection brings new challenges for the original equipment manufacturers and the governing authorities. Introduction of Pedestrian Protection regulation, a recent development in the automotive industry, has thrown several questions in front of original equipment manufacturers. This work explains the procedure to address such question and the learning associated with it.
2016-02-01
Technical Paper
2016-28-0050
Deepak Agrawal, Sharad Rawat, A. K. Upadhyay
Abstract Corrugated tubes are one among the different types of energy absorbers being used for the protection of passengers during impact /crash events of vehicles. Present work is primarily focused to analyze the effect of the variations of wavelength and amplitude of corrugation along the length of the tube on the crashworthiness of the tube. The circumferential corrugations in the tubes are graded by varying two parameters - wavelength and amplitude individually as well as simultaneously using different sinusoidal corrugation functions. The dynamic impact analysis has been carried out using LS-DYNA FEM code using shell elements for meshing and Magnesium alloy AZ31 as material. Energy absorbed, initial peak force, mean force and stroke length are the parameters used in this comparative study. It is observed that the initial reaction forces as well as the ratio of the mean reaction force to peak load changes with the grading of corrugation.
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