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Viewing 271 to 300 of 4645
2015-04-14
Technical Paper
2015-01-0516
Nan Wang, Sergey Golovashchenko, Quochung Le
Abstract Experimental results on influence of trimming conditions on the shape of the sheared surface are combined with the results of stretching sheared samples after trimming. The objective of the research described in this paper is to study the mechanism of fracture initiation and cracks propagation during half-a-dog bone tensile test representing sheared edge stretching condition. One side of the sample had sheared surface obtained by the trimming process while the other side of the sample had a smooth surface. Significant attention was paid to understanding of fracture sources. An interrupted tensile test approach was employed to track fracture initiation and propagation during stretching of sheared surface. The results of the experimental study indicated that multiple sources of fracture were observed in the burr area for trimming with clearances exceeding 10% of the material thickness.
2015-04-14
Technical Paper
2015-01-0134
Durga Madhab Mishra, Bimal Kant Gupta
Abstract The Two wheeler motorcycles electrical system consists of a generator, a storage battery, voltage control protective devices and the electrical loads. Battery, in motorcycles, supports the starting, lighting and ignition system. Generally, in a vehicle, headlight or any other electrical apparatus consumes significant amount of current from the battery causing drain of the battery when the vehicle is not running and one of the light or electrical apparatus inadvertently remains on for some time. The present invention relates to vehicle light system and, more particularly, to a light control system of a vehicle. This discloses a concept which, automatically turned off vehicle lighting system when engine is OFF. Present invention named as “Intelligent lighting system” which helps in avoiding drainage of battery in case, when rider switches ON the ignition switch (H/L already ON) & engine OFF.
2015-04-14
Technical Paper
2015-01-1330
Yoshiyuki Tosa, Hiroyuki Mae
Abstract The objective of this study is to accurately predict the dynamic strain on the windshield caused by the deployment of the airbag in a short term without vehicle tests. The following assumption is made as to the dynamic pressure distribution on the windshield: The deployment of the airbag is fast enough to ignore spatial difference in the patterns of the pressure time histories. Given this assumption, significant parameters of the dynamic pressure distribution are as follows: 1) the distribution of the maximum pressure during contact between the airbag and the windshield, and 2) the characteristic of the force time histories applied to the windshield by the deploying airbag. In this study, the prediction method consists of a simplified airbag deployment test and an FE simulation. The simple deployment test was conducted to measure the peak pressure distribution between the airbag and a flat panel simulating the windshield.
2015-04-14
Technical Paper
2015-01-1462
Seung Jun Yang
Abstract Each year, more than 270,000 pedestrians lose their lives on the world's roads. Globally, pedestrians constitute 22% of all road traffic fatalities, and in some countries this proportion is as high as two thirds of all road traffic deaths. Millions of pedestrians are non-fatally injured and some of whom are left with permanent disabilities. These incidents cause much suffering and grief as well as economic hardship. To lower the rate of pedestrian injuries and fatalities, the Euro-Ncap committee adopted an overall impact star-grade system in 2009, making the pedestrian protection cut-off score required to obtain the best impact-star grade more stringent until 2016. It is very difficult to surpass the enhanced pedestrian cut-off score using past methods. In this paper, I determine the hood's worst-performing areas in terms of pedestrian protection by analyzing previous pedestrian test results.
2015-04-14
Technical Paper
2015-01-1493
Vinay L. Virupaksha, Stuart Brown
Abstract Research Council for Automotive Repairs (RCAR) has developed a bumper test at 10 km/h to assess the damageability and repairing cost during a low speed collusion. For minimum damage and minimum repairing cost during low speed collusion it is necessary to design a bumper beam which provides structural stiffness and reduced deflection. Often it is challenging to design a front bumper beam to meet all safety requirements including, RCAR, high speed offset barrier and pedestrian protection, since these requirements are not necessarily compatible with each other. Design changes in rails and packaging constraints add to this challenge. In this study, design of six sigma (DFSS) and finite element analysis are used to study the parameters that affect the stiffness and deflection of the front bumper beam.
2015-04-14
Journal Article
2015-01-1482
Bisheshwar Haorongbam, Anindya Deb, Clifford Chou
Abstract Hat-sections, single and double, made of steel are frequently encountered in automotive body structural components. These components play a significant role in terms of impact energy absorption during vehicle crashes thereby protecting occupants of vehicles from severe injury. However, with the need for higher fuel economy and for compliance to stringent emission norms, auto manufacturers are looking for means to continually reduce vehicle body weight either by employing lighter materials like aluminum and fiber-reinforced plastics, or by using higher strength steel with reduced gages, or by combinations of these approaches. Unlike steel hat-sections which have been extensively reported in published literature, the axial crushing behavior of hat-sections made of fiber-reinforced composites may not have been adequately probed.
2015-04-14
Journal Article
2015-01-0485
Mehdi Modares, Joshua Bergerson
Abstract In order to ensure the safety of a structure, adequate strength for structural elements must be provided. Moreover, catastrophic deformations such as buckling must be prevented. Using the linear finite element method, deterministic buckling analysis is completed in two main steps. First, a static analysis is performed using an arbitrary ordinate applied loading pattern. Using the obtained element axial forces, the geometric stiffness of the structure is assembled. Second, an eigenvalue problem is performed between structure's elastic and geometric stiffness matrices, yielding the structure's critical buckling loads. However, these deterministic approaches do not consider uncertainty the structure's material and geometric properties. In this work, a new method for finite element based buckling analysis of a structure with uncertainty is developed.
2015-04-14
Journal Article
2015-01-1377
Hiroshi Yokoyama, Atsushi Otani, Naoyuki Shirota, Takao Umezawa
Abstract As an integral element of automotive wiper systems, an automotive washer system is designed to contribute to the security and safety of automobile-based societies by providing drivers with a clear field of vision. Washer fluid is discharged from washer nozzles, typically mounted on the engine hood, to distances of more than 300 mm across the windshield. However, the fluid discharged may fail to reach targeted areas due to the effects of wind pressure when the vehicle is moving at high speed or due to the increased viscosity of methanol in the washer fluid (at concentrations of 30-60 %) at low temperatures, resulting in failure to ensure a clear field of vision. We developed a self-oscillating washer nozzle to remedy these shortcomings of conventional washer systems. Based on CFD and optimization, the flow passage is designed to generate a stable discharge of washer fluid, even under conditions of high-speed air flow or low temperature.
2015-04-14
Journal Article
2015-01-0417
Akira Yamada, Shunsuke Iwao
Abstract An exterior light lens with a unique and finely textured shape was devised, which provides homogenous luminance, and luminance control technology of exterior light by arranging finely textured shape was developed. Because a die mold with a fine, three-dimensional lens shape is required when mass-producing the lens, we also developed a CAM (Computer Aided Manufacturing) that enables finely textured machining on a free-form surface and automatically produces a smooth machining path on a curved surface. This new technology allowed us to successfully develop a lens that simultaneously achieves transparency and homogenous luminance, properties not achievable through conventional technology.
2015-04-14
Journal Article
2015-01-0484
Naijia Xiao, Rafi L. Muhanna, Francesco Fedele, Robert L. Mullen
Abstract We analyze the frequency response of structural dynamic systems with uncertainties in load and material properties. We introduce uncertainties in the system as interval numbers, and use Interval Finite Element Method (IFEM). Overestimation due to dependency is reduced using a new decomposition for the stiffness and mass matrices, as well as for the nodal equivalent load. In addition, primary and derived quantities are simultaneously obtained by means of Lagrangian multipliers that are introduced in the total energy of the system. The obtained interval equations are solved by means of a new variant of the iterative enclosure method resulting in guaranteed enclosures of relevant quantities. Several numerical examples show the accuracy and efficiency of the new formulation.
2015-04-14
Journal Article
2015-01-0694
Tadashi Naito, Yuta Urushiyama
Abstract The strength characteristic of CFRP composite materials is often dependent on the internal micro-structural fracture mode. When performing a simulation on composite structures, it is necessary to take the fracture mode into account, especially in an automobile body structure with a complex three-dimensional shape, where inter-ply fractures tend to appear due to out-of-plane load inputs. In this paper, an energy-based inter-ply fracture model with fracture toughness criteria, and an intra-ply fracture model proposed by Ladeveze et al. were explained. FEM analyses were performed on three-dimensional test specimens applying both fracture models and the simulated results were compared with experimental ones. Reproducibility of the fracture mode was confirmed and the importance of combining both models was discussed.
2015-04-14
Journal Article
2015-01-0729
Anshul Mittal, Anindya Deb, Clifford Chou
Abstract Rapid progress in the interdisciplinary field of automotive engineering and the pressing need for an environmental friendly alternative to metal and synthetic fiber-reinforced composites for vehicle structure have triggered recent research in the field of natural fiber-based composites. Their potential advantages are attributed to their light weight, low cost and biodegradability. However, their usage in present day automotive systems is restricted due a lower magnitude range of mechanical properties and limited study in this area. In contrast to mechanical joints, the adhesively bonded joints aid in reducing stress concentration, joining of dissimilar materials, corrosion prevention, weight reduction and a smoother finish. Thus, in the present study, failure load, and mean shear stress of single lap shear and double lap shear joints as a function of joint overlap length, are evaluated using a two part epoxy adhesive made by Huntsman.
2015-04-14
Journal Article
2015-01-0709
Xiaoqing Xu, Bohan Liu, Yibing Li
Abstract Polyvinyl butyral (PVB) film and SentryGlas® Plus (SGP) film have been widely used in automotive windshield and architecture curtain serving as protective interlayer materials. Viscoelasticity is the unique property of such film materials, which can contribute to improving impact resistance and energy absorbing characteristics of laminated glass. In this study, the uniaxial tensile creep and stress relaxation tests are conducted to investigate the viscoelasticity of PVB and SGP films used in laminated glass. Firstly, tensile creep and stress relaxation tests of PVB film (0.76mm) and SGP film with three thickness (0.89mm, 1.14mm and 1.52mm) are conducted using Instron universal testing machine to obtain creep and stress relaxation curves. Afterwards, both viscoelastic models (Burgers model, Maxwell-Weichert model) and empirical equations (Findley power law, Kohlrausch equation) are applied to simulate the creep and stress relaxation results.
2015-04-14
Journal Article
2015-01-0722
Mathieu Imbert
Abstract High speed Reactive Resin Transfer Moulding (RTM) is a promising process for the mass production of structural composite parts in the automotive industry. In this technology a low viscosity reactive thermosetting or thermoplastic polymer is injected in a fibrous preform made of glass or carbon fibres fabrics. Continuous fibre reinforcements contain two types of volume to be impregnated: microscopic voids inside the fibre tows and mesoscopic ones between the tows. Because of this double-scale structure, the saturation of fabrics with bi-disperse porous structure is not instantaneous during resin injection. The use of reactive resins aims to reduce both the resin viscosity and part cycle time by beginning curing during the filling stage. However the chemical reactions generate significant evolution in the temperature, composition and properties of the resin during injection, which can affect the filling and quality of the part.
2015-04-14
Technical Paper
2015-01-1367
Guan Zhou, Guangyao Li, Aiguo Cheng, Guochun Wang, Hongmin Zhang, Yi Liao
Abstract Lightweight has been the main focus of the auto industry in recent years. To improve the competitiveness, the weight reduction should be achieved without compromising the performance. A new lightweight strategy of auto body is proposed in this research to improve the efficiency of the traditional lightweight method. Topology optimization is first applied to find the weak part of the BIW (Body-In-White) and small size parts are added to improve the overall performance. Punching and shape cutting are also applied in this step to reduce the material area. This will maximize the potential for the later lightweight. Sensitivity analysis is then applied in this study to optimize the plate thickness. By optimizing the thickness, the weight of the BIW reduced significantly. The various performance verifications were carried out to verify the efficiency of the optimization.
2015-04-14
Technical Paper
2015-01-1378
Takeshi Sasaki, Tatsuya Ohmaru, Taisuke Goto
Abstract We developed a windshield washer system that enhances washing performance while maintaining low consumption of windshield washer fluid. The system reduces user stress by shortening the amount of time required to remove dirt and maintaining visibility through the windshield. We analyzed the mechanism through which the windshield wiper and windshield washer remove dirt from the glass surface to improve cleaning efficiency. The mechanism consists of a sequence in which the windshield washer fluid splashes down on the glass surface and lifts dirt which is then wiped away by the windshield wiper blade. We defined the amount of windshield washer fluid needed and the time from splashdown to wiping required to lift dirt and wipe it away with the wiper. Based on this mechanism, we developed a wiper arm with built-in washer nozzles.
2015-04-14
Technical Paper
2015-01-1318
Mohammad Muneer, Yogesh Sharma
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.
2015-04-14
Journal Article
2015-01-1376
Thomas Leonhard, Thomas Cleary, Michael Moore, Shane Seyler, W Keith Fisher
Abstract This paper proposes a novel concept for lightweight vehicle design, offering a step change in weight reduction for automotive glazing. Reducing window weight can be achieved by decreasing the thickness of the glass plies used to form vehicle windows. However, reducing the thickness of conventional automotive windows also decreases its effective strength; therefore, concerns about glass breakage become a limiting factor for weight reduction. Chemically strengthened ultrathin Corning® Gorilla® Glass offers the potential to go beyond existing thickness limitations. Its higher strength compared to standard soda lime window glass allows the design of thin, low weight window constructions. In addition, its unique manufacturing process delivers pristine glass surfaces and precise thickness control for high quality window optics. While this concept can be applied to all vehicle openings, this study focuses on automotive windshield design.
2015-04-14
Technical Paper
2015-01-0581
Luke Deptula, Alaa Noah
The approaching corporate average fuel economy (CAFE) regulations will again increase with new model years (MY). The U.S. Government finalized a regulation requiring cars and light trucks average 54.5 mpg fuel economy for MY2025. Vehicle manufacturers recognize removing weight is a key feature to meeting their targets for fuel economy and emission reductions. One common OEM strategy is the implementation of incremental weight reductions to attain these goals. The automotive industry continues to look for opportunities to reduce weight and cost while continually increasing performance and safety. Lightweighting technologies enhance vehicle performance, (fuel economy, acceleration, braking and emissions). New materials are available to reduce weight; however the incremental cost for the weight reduction can be prohibitive. This study will encompass the utilization of lightweight materials, as well as current and evolving manufacturing processes.
2015-04-14
Technical Paper
2015-01-1467
Chinmoy Pal, Tomosaburo Okabe, Kulothungan Vimalathithan, Jeyabharath Manoharan, Munenori Shinada
Abstract Logistic regression analysis for accident cases of NASS-PCDS (National Automotive Sampling System-Pedestrian Crash Data Study) clearly shows that the extent and the degree of pedestrian's lower extremity injury depend on various factors such as the impact speed, the ratio of the pedestrian height to that of the bonnet leading edge (BLE) of the striking vehicle, bumper to knee ratio, bumper lead angle, age of the pedestrian, and posture of the pedestrian at the time of impact. The pedestrian population is divided in 3 groups, equivalent to small-shorter, medium-height and large-taller pedestrian with respect to the “pedestrian to BLE height-ratio” in order to quantify the degree of influence of lower leg injuries in each group. Large adult male finite element model (95th percentile male: 190 cm and 103 kg) was developed by morphing the Japan Automobile Manufacturers Association (JAMA) 50th percentile male.
2015-04-14
Technical Paper
2015-01-0369
Rupesh Sonu Kakade
Abstract In addition to the thermal comfort of the vehicle occupants, their safety by ensuring adequate visibility is an objective of the automotive climate control system. An integrated dew point and glass temperature sensor is widely used among several other technologies to detect risk of fog formation on the cabin side (or inner) surface of the windshield. The erroneous information from a sensor such as the measurement lag can cause imperfect visibility due to the delayed response of the climate control system. Also the high value, low cost vehicles may not have this sensor due to its high cost. A differential equation based model of the cabin air humidity is proposed to calculate in real-time specific humidity of the passenger compartment air. The specific humidity is used along with the windshield surface temperature to determine relative humidity of air and therefore, the risk of fog formation on the interior surface of a windshield.
2015-04-14
Technical Paper
2015-01-0727
Udayakumar Rajamanickam, Anshul Singhal, Miller Jothi
Abstract This paper aims at Fiber Reinforced Panel or FRP mold and panel manufacturing of body panel and driver seat for a Formula Society of Automotive Engineers or FSAE racecar. The competition involves designing a Formula 1 type car that lays the standards for a high performance-racing car [1]. This calls for a high Power: Weight ratio. The rules of the competition ensure a mandatory use of an air restrictor with an engine of a maximum capacity of 600cc to reduce the power of the engines [2]. Hence, to compensate for the loss of power the target now shifts to minimizing the car's weight without compromising the strength. The body panel and driver's seat are two most valuable parts as the first adds elegance and aerodynamics to the car while the latter makes it comfortable for the driver to drive the car under high lateral load shifts. Weight reduction in this area is easier as strength is not the dominating factor.
2015-04-14
Technical Paper
2015-01-0702
Bita Ghaffari, Jonathan Dekam, Kevin Haddix, Kimberly Lazarz, Sergey Titov, Roman Maev
Abstract Adhesive bonding technology has gained ever-increasing significance in automotive industry, especially with the growing use of aluminum (Al) alloy body structures. The variability in thicknesses of the metal and adhesive layers, as well as in joint geometry, of automotive components has presented challenges in nondestructive evaluation of adhesive joints. Though these challenges were recently overcome for steel-adhesive joints using an ultrasonic pulse-echo technique, the difference in acoustic impedances of steel and Al leads to a lack of robustness in utilizing the same algorithm for Al-adhesive joints. Here, we present the results from using a modified version of this technique to inspect Al-adhesive joints in both laboratory and production environments. A 15-MHz, 52-pixel, 10 mm × 10 mm matrix array of ultrasonic transducers was used to obtain ultrasonic pulse echoes from joint interfaces, analysis of which produced C-scan images of the adhesive bead.
2015-04-14
Technical Paper
2015-01-0559
Cheryl Caffrey, Kevin Bolon, Greg Kolwich, Robert Johnston, Timothy Shaw
Abstract The United States Environmental Protection Agency contracted with FEV North America, Inc. to conduct a whole vehicle analysis of the potential for mass reduction and related cost impacts for a future light-duty pickup truck. The goal was to evaluate the incremental costs of reducing vehicle mass on a body on frame vehicle at levels that are feasible in the 2020 to 2025 model year (MY) timeframe given the design, material, and manufacturing processes likely to be available, without sacrificing utility, performance, or safety. The holistic, vehicle-level approach and body-structure CAE modeling that were demonstrated in a previous study of a mid-sized crossover utility vehicle were used for this study. In addition, evaluations of closures performance, durability, and vehicle dynamics that are unique to pickup trucks are included. Secondary mass reduction was also analyzed on a part by part basis with consideration of vehicle performance requirements.
2015-04-14
Technical Paper
2015-01-0673
Rohit Ray, Nagarjun Jawahar
Abstract Automotive OEM's are looking to develop plastic parts with maximum life and durability through virtual simulations with help of CAE tools, thereby saving the mold cost, material cost and time. The design constrains would be manufacturability, loads, boundary condition and aesthetics. This work involves the multi-discipline approach to virtually visualize the effect of fluid structure interaction due to splashing on the rear fender of a motorcycle which acts as mud guard. This study shows effect of splashing of water over rear fender on wet roads. First, the pressure developed on the rear fender due to impingement of water on surface is obtained through a multiphase volume of fluid analysis using CFD software Fluent. Secondly, these pressure values are taken as input in Abaqus software and the part is analyzed for its durability.
2015-04-14
Technical Paper
2015-01-1362
Chao Li, Il Yong Kim
Abstract A bumper system plays a significant role in absorbing impact energy and buffering the impact force. Important performance measures of an automotive bumper system include the maximum intrusions, the maximum absorbed energy, and the peak impact force. Finite element analysis (FEA) of crashworthiness involve geometry-nonlinearity, material-nonlinearity, and contact-nonlinearity. The computational cost would be prohibitively expensive if structural optimization directly perform on these highly nonlinear FE models. Solving crashworthiness optimization problems based on a surrogate model would be a cost-effective way. This paper presents a design optimization of an automotive rear bumper system based on the test scenarios from the Research Council for Automobile Repairs (RCAR) of Europe. Three different mainstream surrogate models, Response Surface Method (RSM), Kriging method, and Artificial Neural Network (ANN) method were compared.
2015-04-14
Technical Paper
2015-01-1549
Jonathan Jilesen, Adrian Gaylard, Iwo Spruss, Timo Kuthada, Jochen Wiedemann
Abstract Driving when it is raining can be a stressful experience. Having a clear unobstructed view of the vehicles and road around you under these conditions is especially important. Heavy rain conditions can however overwhelm water management devices resulting in water rivulets flowing over the vehicle's side glass. These rivulets can significantly impair the driver's ability to see the door mirror, and laterally onto junctions. Designing water management features for vehicles is a challenging venture as testing is not normally possible until late in the design phase. Additionally traditional water management features such as grooves and channels have both undesirable design and wind noise implications. Having the ability to detect water management issues such as A-pillar overflow earlier in the design cycle is desirable to minimize the negative impact of water management features. Numerical simulation of windscreen water management is desirable for this reason.
2015-04-14
Technical Paper
2015-01-1558
Amir Kharazi, Edward Duell, Austin Kimbrell, Ann Boh
Abstract Unsteady flow over automotive side-view mirrors may cause flow-induced vibrations of the mirror assembly which can result in blurred rear-view images, adversely affecting marketability through customer comfort and quality perception. Prior research has identified two mechanisms by which aerodynamically induced vibrations are introduced in the mirror. The first mechanism is unsteady pressure loading on the mirror face due to the unsteady wake, causing direct vibration of the mirror glass. The second mechanism, and the focus of this study, is a fluctuating loading on the mirror housing caused by an unsteady separation zone on the outer portion of the housing. A time-dependent Computational Fluid Dynamics (CFD) methodology was developed to correctly model mirror wake behavior, and thereby predict flow-induced mirror vibration to improve performance estimations.
2015-04-14
Technical Paper
2015-01-1528
Kenichi Hirose, Rina Nakagawa, Yukitaka Ura, Hideyuki Kawamata, Hisashi Tanaka, Munehiko Oshima
Abstract It is considered that door mirror drag is composed of not only profile drag but also interference drag that is generated by the mixing of airflow streamlines between door mirrors and vehicle body. However, the generation mechanism of interference drag remained unexplained, so elucidating mechanism for countermeasures reducing drag have been needed. In this study, the prediction formulas for door mirror drag expressed by functions in relation to velocities around the vehicle body were derived and verified by wind tunnel test. The predicted values calculated by formulas were compared with the measured values and an excellent agreement was found. In summary, new prediction formulas made it possible to examine low drag mirror including profile and interference drag.
2015-04-14
Technical Paper
2015-01-1542
Masaaki Arai, Keitaro Tone, Keiichi Taniguchi, Mikako Murakami, Munehiko Oshima
Abstract The new Murano was developed with special emphasis on improving aerodynamics in order to achieve fuel economy superior to that of competitor models. This paper describes the measures developed to attain a drag coefficient (CD) that is overwhelmingly lower than that of other similar models. Special attention was paid to optimizing the rear end shape so as to minimize rear end drag, which contributes markedly to the CD of sport utility vehicles (SUVs). A lower grille shutter was adopted from the early stage of the development process. When open, the shutter allows sufficient inward airflow to ensure satisfactory engine cooling; when closed, the blocked airflow is actively directed upward over the body. The final rear end shape was tuned so as to obtain the maximum aerodynamic benefit from this airflow. In addition, a large front spoiler was adopted to suppress airflow toward the underbody as much as possible.
Viewing 271 to 300 of 4645