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2017-03-28
Technical Paper
2017-01-0231
Shih-Po Lin, Yijung Chen, Danielle Zeng, Xuming Su
In the conventional approach, the material properties of laminate composites for crash simulations are typically obtained from standard coupon tests, where the test results only provide single layer material properties. However, the lay-up effects for the failure behaviors of the real structure were not considered in numerical simulations. Hence, there was discrepancy between the crash simulations and experimental tests. Consequently, an intermediate stage is required for accurate predictions. Some component tests are required to calibrate the material models in the intermediate stage. In this paper, a laminate cylinder tube under high-impact velocity in the direction of tube axis is chosen as an example for the crash analysis. The tube consists of 24 layers of uni-directional (UD) carbon fiber composite materials, in which 4 layers are perpendicular to, while the other layers are parallel to the impact direction.
2017-03-28
Technical Paper
2017-01-0396
Guobiao Yang, Changqing Du, Dajun Zhou, Hao Wang, Elizabeth Lekarczyk, Lianxiang Yang
Abstract Vehicle weight reduction is a significant challenge for the modern automotive industry. In recent years, the amount of vehicular components constructed from aluminum alloy has increased due to its light weighting capabilities. Automotive manufacturing processes, predominantly those utilizing various stamping applications, require a thorough understanding of aluminum fracture predictions methods, in order to accurately simulate the process using Finite Element Method (FEM) software or use it in automotive engineering manufacture. This paper presents the strain distribution of A5182 aluminum samples after punch impact under various conditions by Digital Image Correlation (DIC) system, its software also measured the complete strain history, in addition to sample curvature after it was impacted; therefore obtaining the data required to determine the amount of side-wall-curl (Aluminum sheet springback) present after formation.
2017-03-28
Technical Paper
2017-01-0467
Wei Yuan, Brian Jordon, Bita Ghaffari, Harish Rao, Shengyi Li, Min Fan
Abstract Lightweight metals such as Al and Mg alloys have been increasingly used for reducing mass in both structural and non-structural applications in transportation industries. Joining these lightweight materials using traditional fusion welding techniques is a critical challenge for achieving optimum mechanical performance, due to degradation of the constituent materials properties during the process. Friction stir welding (FSW), a solid-state joining technique, has emerged as a promising method for joining these lightweight materials. In particular, high joining efficiency has been achieved for FSW of various Al alloys and Mg alloys separately. Recent work on FSW of dissimilar lightweight materials also show encouraging results based on quasi-static shear performance. However, coach-peel performance of such joints has not been sufficiently examined.
2017-03-28
Technical Paper
2017-01-0472
Gyoko Oh
Abstract To prevent corrosion of the inlet part with aqueous ammonia injection, high chromium corrosion-resistant materials have been applied for welded joints of mufflers. Bending fatigue strength of welded joint samples of flange pipes was defined through fatigue experiments, modeling that high fluctuating stresses exist in the inlet and outlet flange pipes of a muffler caused by the vibration of a moving vehicle. Factors that caused fatigue to failure such as welding bead shape and metallographic structure were identified through local stress measurements, FEM stress simulations, microscopic observations, and SEM-EDS composition analyses. By comparing with sample A having a smaller flank angle and sample B having a larger flank angle, the results suggested that the difference of bending fatigue strengths at 200,000 cycles was 24% when based on nominal stress, and the difference was 10% when based on measured maximum stress.
2017-03-28
Technical Paper
2017-01-0474
Chady Khalil, Yannick Amosse, Guillaume Racineux
Abstract In this study, a proposed new 3-in-1 process using the magnetic pulse welding (MPW) for welding similar and dissimilar metals and for hybrid joining between FRC and metals is developed. Welding between (a) AA1199 sheets and XES, (b) AA1199 and XSG which is zinc coated steel, (c) 5754-aluminum alloy and XES were performed and (d) hybrid joint between PA66-glass-FRC and 5754-aluminum was achieved. SEM observations and EDX analysis for the weld interface between aluminum and steel showed where detectable very thin layers of intermetallics and the wavy interface pattern typical for impact welding was identified. X-Ray microtomography observation for the joining region in the FRC showed the good state of the composite structure after joining. 3D numerical simulation using LS-Dyna was used for the selection of the welding parameters. Quasi-static lap shear testing for the welds revealed a failure in the weak metal sheet and not in the weld.
2017-03-28
Technical Paper
2017-01-0471
Yasuo Kadoya, Yuki Oshino
Abstract By implementation of the core technology of capacitor-resistance welding, RingMash technology, metallic bonding, is developed to manufacture various components. It is the best suited for powertrain components such as transmission gears at low cost. Components made by RingMash are attributed to smaller and lighter transmission. The technology is recommended to manufacture co-axle male-female work pieces bonding, male side diameter is slightly larger than female side hole. RingMashing is a solid state bonding without melting work pieces. The actual RingMashing process is done in ambient atmosphere and does not use filler. RingMashing process itself takes only 100 milliseconds, results very minimum Heat-Affected Zone (HAZ), normally no more than 1 mm. The minimum HAZ achieves excellent structural integration for better performance of transmission. If two work pieces are same metals, spattering free bonding is possible.
2017-03-28
Technical Paper
2017-01-0479
Soichi Hareyama, Ken-ichi Manabe, Makoto Nakashima, Takayuki Shimodaira, Akio Hoshi
Abstract This investigation describes a method for estimating the absolute lock effect in bolted joint. Observation results of loosening phenomenon in industrial vehicle are analyzed for the linear relation by the proposed regression formula. Based on the relation, in early stages of the development test, the rate of clamping force decrease can be estimated accurately after prolonged operation by measuring the clamping force behavior. The tendency to decrease is observed about the depression type and working load type loosening. For evaluation design bases, the residual clamping force estimation chart is established. The L-N (Loosening Lifetime - Number of Cycles to Loosening N) diagram is proposed for the loosening lifetime prediction for working load type loosening also. Using the loosening damage (cumulative decrease of clamping force) and L-N diagram, the lifetime to loosening failure can be predicted accurately for the locking device and method as an absolute evaluation.
2017-03-28
Technical Paper
2017-01-0506
Xueyuan Nie, Jimi Tjong
Abstract Ultra-high strength steel (UHSS) and magnesium (Mg) alloy have found their importance in response to automotive strategy of light weighting. UHSS to be metal-formed by hot stamping usually has a hot-dipped aluminum-silicon alloy layer on its surface to prevent the high temperature scaling during the hot stamping and corrosion during applications. In this paper, a plasma electrolytic oxidation (PEO) process was used to produce ceramic oxide coatings on aluminized UHSS and Mg with intention to further improve their corrosion resistances. A potentiodynamic polarization corrosion test was employed to evaluate general corrosion properties of the individual alloys. Galvanic corrosion of the aluminized UHSS and magnesium alloy coupling with and without PEO coatings was studied by a zero resistance ammeter (ZRA) test. It was found that the heating-cooling process simulating the hot stamping would reduce anti-corrosion properties of aluminized UHSS due to the outward iron diffusion.
2017-03-28
Technical Paper
2017-01-0489
Hyunkwon Jo, Jongsoo Kim, Jaemin Park, Heeseung Yang, Hyunmin Park
Abstract Cost reduction is an important issue in the intense competition automotive industry. Interior parts which are mainly consist of plastic have same issue. The manufacturing main processes of plastic products are injection and assemble and the cost of injection depends on injection cycle time. Therefore many studies for the reduction of injection cycle time have been implemented. However the researches based on engineer's experiences have limits so, nowadays many studies utilize CAE. In this paper, the study for the reduction of cycle time focused on injection molding design. To satisfy appearance quality with the reduction of cycle time, the design of injection molding was optimized by using CAE. The result of CAE showed many causes and effects of problems. The optimization of injection molding design improved the quality with the reduction of cycle time. Finally, the product based on CAE showed good quality and cycle time reduction in comparison with previous products.
2017-03-28
Technical Paper
2017-01-1240
Koki Matsushita
Abstract For the purpose of improving vehicle fuel efficiency, it is necessary to reduce energy loss in the alternator. We have lowered the resistance of the rectifying device and connecting components, and control the rectifying device with an IC to reduce rectification loss. For the package design, we have changed the structure of the part on which the rectifying device is mounted into a high heat dissipation type. The new structure has enabled optimizing the size of the rectifying device, resulting in the reduction of size of the package. In addition, the rectifying device is mounted using a new soldering material and a new process, which has improved the reliability of the connection. Moreover, since the alternator has introduced a new system, the controller IC has a function for preventing malfunction of the rectifying device and a function for detecting abnormalities, in order to ensure safety.
2017-03-28
Technical Paper
2017-01-1537
Ananya Bhardwaj
Abstract Improving brake cooling has commanded substantial research in the automotive sector, as safety remains paramount in vehicles of which brakes are a crucial component. To prevent problems like brake fade and brake judder, heat dissipation should be maximized from the brakes to limit increasing temperatures. This research is a CFD investigation into the impact of existing wheel center designs on brake cooling through increased cross flow through the wheel. The new study brings together the complete wheel and disc geometries in a single CFD study and directly measures the effect on brake cooling, by implementing more accurately modeled boundary conditions like moving ground to replicate real conditions correctly. It also quantifies the improvement in the cooling rate of the brake disc with a change in wheel design, unlike previous studies.
2017-03-28
Technical Paper
2017-01-1709
Zhigang Wei, Sarat Das, Ryan Barr, Greg Rohrs, Robert Rebandt, Xiao Wu, HongTae Kang
Abstract Recent stringent government regulations on emission control and fuel economy drive the vehicles and their associated components and systems to the direction of lighter weight. However, the achieved lightweight must not be obtained by sacrificing other important performance requirements such as manufacturability, strength, durability, reliability, safety, noise, vibration and harshness (NVH). Additionally, cost is always a dominating factor in the lightweight design of automotive products. Therefore, a successful lightweight design can only be accomplished by better understanding the performance requirements, the potentials and limitations of the designed products, and by balancing many conflicting design parameters. The combined knowledge-based design optimization procedures and, inevitably, some trial-and-error design iterations are the practical approaches that should be adopted in the lightweight design for the automotive applications.
2017-03-28
Technical Paper
2017-01-1321
Meisam Mehravaran, Yi Zhang
Abstract Degas bottles have been extensively used in vehicles in order to act as an air pillow on top of the cooling loop and provide space for expansion. One of the important characteristics of the bottle which defines if it will work in a certain loop is the so called “capacity” of the bottle which defines the flowrate that degas bottle would be able to pass through without any foaming. Considering the complex geometry of degas bottle and the foaming phenomena, predicting the behavior of coolant in the bottle passages is challenging which requires costly tests. Computational Fluid Dynamics (CFD) has been extensively used in simulating multi-phase flows in automotive components. In the current project, CFD has been used to simulate the behavior of flow in bottle chambers and to provide guidelines for the design team in order to increase the bottle performance/capacity. The CFD guidelines were in agreement with test results and lead to improving the degas bottle capacity.
2017-03-28
Technical Paper
2017-01-1323
Jerry Lai, Youssef Ziada, Juhchin Yang
Abstract In the assembly of axles and wheel hubs, a nut is frequently used to fasten them as one unit. In order for the nut to hold the assembly in its final position, crimping is a widely-used method which prevents nut from loosening. A reliable crimping process not only prevents movement of the nut during axle operation but should also minimize the possibility of cracking the rim. If the nut cracks during assembly, it can start to rust and deteriorate. The service life span of the axle assembly hence shortens as a result. The quality of crimping operation is determined by the component designs, the process parameters, and the crimping tool geometry. It would be time-consuming and costly to evaluate these factors empirically; let alone the requirement of prototypes in the early stage of a new program. A dynamic finite element methodology which adopts the Arbitrary Lagrangian-Eulerian formulation from ABAQUS explicit solver is developed to simulate the complete crimping process.
2017-03-28
Technical Paper
2017-01-0254
Sudeep Chavare, Kevin Thomson, Nitin Sharma
Adopting parametric approach to optimize CAE models for various objectives is a common practice these days. Connection entities such as welds and adhesive play a very important role in overall performance matrix and hence adding them to the pool of design variables during an optimization exercise provides additional design space. This paper evaluates the possibility to use structural adhesives as patches rather than continuous lines. The method presented in this paper offers unique approach to parameterize adhesive lines. The paper discusses an optimization study with structural adhesives patches along with spot weld pitch as design variables. Body in White (BiW) and Trimmed Body in White (TBiW) models are used for analysis .The goal of the study is to reduce total length of structural adhesive as well as number of welds while maintaining baseline NVH performance as constraints.
2017-03-28
Technical Paper
2017-01-0255
Malli Kartheek Yalamanchili, Nitin Sharma, Kevin Thomson
The crashworthiness of body-in-white (BIW), plays a very vital role in the full vehicle crash performance. The structural integrity of BIW is controlled via strength of the spot welds and adhesives that are often considered as only entities to hold the parts together. However optimizing the welds and/or adhesives can not only reduce the number of connections but also improve the structural crashworthiness. This paper discusses the optimization of full vehicle structural performance and the length of adhesives in the BIW for the small overlap crash event. The variables included in the study were length of the adhesives and gage variables, defined in the front end structure of the vehicle. A parametric model was created using ANSA and iSight was used to generate design of experiments (DOE). Automated design generation using ANSA followed by automated script based post-processing was done. The optimization was done using metamodel generated for the crash event.
2017-03-28
Technical Paper
2017-01-1264
Gregory L. Talbert, Edward John Vinarcik
Abstract 6061-O temper extruded rod may be used as feed stock in forming processes for automotive pressure vessel applications. Key parameters for forming are the strength and hardness of the material. The purpose of this paper was to reduce variation in hardness to achieve a process capability index of 1.33 or greater. Among the process steps affecting hardness, annealing is the most critical. Initially, the process showed unacceptable hardness variation. Initial anneal recipes called for a 4-hour soak at 775°F (413°C). Initial process capability for hardness was a Cpk of 1.12, with tensile strength readings very close to the upper specification limit. Initial temperature uniformity surveys of the anneal oven showed a large variation in temperature distribution, with some areas of the oven staying below 650°F (343°C). Initial improvement efforts focused on soak time.
2017-03-28
Technical Paper
2017-01-1225
Jayaraman Krishnasamy, Martin Hosek
Abstract An advanced electric motor with hybrid-field topology has been developed for automotive traction applications. Departing from the conventional radial- and axial-field designs, the hybrid-field motor features three-dimensional magnetic flux paths, which are enabled by a novel isotropic soft magnetic material produced by a unique additive-manufacturing process based on spray forming. The motor is expected to offer an unprecedented combination of high power output, compact size, low weight and energy efficiency, achieving more than two times higher power density than state-of-the-art high-performance traction motors.
2017-03-28
Journal Article
2017-01-1472
Niels Pasligh, Robert Schilling, Marian Bulla
Abstract Rivets, especially self-piercing rivets (SPR), are a primary joining technology used in aluminum bodied vehicles. SPR are mechanical joining elements used to connect sheets to create a body in white (BiW) structure. To ensure the structural performance of a vehicle in crash load cases it is necessary to describe physical occurring failure modes under overloading conditions in simulations. One failure mode which needs to be predicted precisely by a crash simulation is joint separation. Within crash simulations a detailed analysis of a SPR joint would require a very high computational effort. The conflict between a detailed SPR joint and a macroscopic vehicle model needs to be solved by developing an approach that can handle an accurate macroscopic prediction of SPR behavior with a defined strength level with less computational effort. One approach is using a cohesive material model for a SPR connection.
2017-03-28
Technical Paper
2017-01-1239
Naoya Take, Takuya Kadoguchi, Masao Noguchi, Kimihiro Yamanaka
Abstract Power modules are used to operate three-phase alternating current motors in hybrid vehicles and electric vehicles. Good fuel efficiency and high power density are required in the field of hybrid vehicles. To achieve this goal, the miniaturization of the power module will be necessary. This trend may make a current density, which is created by insulated gate bipolar transistors (IGBTs) and free wheel diodes (FWDs), higher in power modules. Solder is often used as the joint material of power modules. It is known that a current density larger than 10 kA/cm2 causes solder electromigration. This phenomenon may cause delamination of the joint area. In addition, the ambient temperature has an influence on electromigration. The temperature of an engine compartment is high, so it is likely to cause electromigration. However, the current density of the double-sided cooling power modules in 2007 with solder joint is lower than 0.4 kA/cm2, and this value is lower than 10 kA/cm2.
2017-03-28
Technical Paper
2017-01-0394
Junrui Li, Ruiyan Yang, Zhen Li, Changqing Du, Dajun Zhou, Lianxiang Yang
Advanced high-strength steel (AHSS) is gaining popularity in the automotive industry due to its higher final part strength with the better formability compares to the conventional steel. However, the edge fracture occurs during the forming procedure for the pre-strained part. To avoid the edge fracture happens during the manufacturing, the effect of pre-strain on edge cracking limit need to be studied. In this paper, digital image correlation (DIC), as a high accuracy optical method, is adopted in the strain measurement for the edge cracking limit determination. Sets of the wide coupons are pre-strained to obtain the samples at different pre-strain level. The pre-strain of each sample is precisely measured during this procedure using DIC. After pre-straining, the half dog bone samples are cut from these wide coupons. The edge of the notch in the half dog bone samples is created by different methods for the distinct edge condition.
2017-03-28
Journal Article
2017-01-0470
Lunyu Zhang, Shin-Jang Sung, Jwo Pan, Xuming Su, Peter Friedman
Structural stress solutions for flow drill screw (FDS) joints in lap-shear specimens of aluminum 6082-T6 sheets with and without clearance hole (without and with gap) are investigated. Analytical structural stress solutions at the critical locations of FDS joints based on the analytical solutions for a rigid inclusion in a thin plate under various loading conditions are first obtained. Finite element analyses are then conducted to verify the analytical solutions. The fatigue life estimations of the FDS joints in lap-shear specimens with and without clearance hole (without and with gap) based on the structural stress solutions are in agreement with those of the experimental results.
2017-03-28
Journal Article
2017-01-0475
Catherine Amodeo, Jwo Pan
The mode I and mode II stress intensity factor solutions for the pre-existing cracks near continuous and discontinuous gas metal arc welds in lap-shear specimens are investigated. Two-dimensional, plane strain finite element analyses were carried out in order to obtain the computational stress intensity factor solutions for the idealized and realistic weld geometries as the references. Then the stress intensity factor solutions for continuous and discontinuous welds were obtained by three-dimensional finite element analyses. The computational results indicate that the distributions of the mode I and mode II stress intensity factor solutions for the discontinuous weld are quite different from those for the continuous weld.
2017-03-28
Technical Paper
2017-01-0481
Xian Jun Sun, Patricia Tibbenham, Jin Zhou, Danielle Zeng, Shiyao Huang, Li Lu, Xuming Su
It is important to investigate on the weld line of injection molded part because the weld line area could induce potential failure for structural application. In this paper, the weld line factor(W-L factor) was adopted to describe the strength reduction to the bulk strength due to the appearance of weld line. There were five engineering thermoplastics involved in this study, including neat PP, talc filled PP, TPO, ABS and PC/ABS. The experimental design was used to investigate on four main injection molding parameters (melt temperature, mold temperature, injection speed and packing pressure). Both the bulk and weld line samples were prepared at each process settings. The sample strength was obtained by the tensile tests under two levels of testing speeds(5mm/min and 200mm/min) and testing temperatures(room temperature and -30oC). The results showed that different materials had various W-L factors. For neat PP, the W-L factor was highest and independent to injection mold parameters.
2017-03-28
Technical Paper
2017-01-0476
Seiji Furusako, Masatoshi Tokunaga, Masanori Yasuyama
In order to reduce the weight of automobile body, application of high strength steel sheets is expanding. And also a middle and high carbon steel is expected to be used to lower the environmental impact and cost in the field of automobile steel sheet. However, it is necesarry for its realization to enhance the joint strengh of the steel sheets. In this study, hat-shape components were made by resistance spot welding or arc-spot welding using S45C steel sheet of 1.4mm in thick with strength of 1200MPa grade . Then dynamice three-point bending test was carried out on the components and crashworthiness of them was compared. Absorbed energy of the arc-spot welded component was higher than that of the resistance spot-welded one by 30%. Some spot welds fractured (separated) during the three-point bending test but arc-spot welds did NOT fractured. Arc-spot welding is therefore seemed to be effective to improve strength and toughness of weld for a middle and high carbon steel sheet.
2017-03-28
Journal Article
2017-01-0477
Harish M. Rao, Jidong Kang, Garret Huff, Katherine Avery, Xuming Su
The use of carbon fiber reinforced polymer (CFRP) composites presents an attractive solution for automotive lightweighting due to the extensive weight savings. One of the key challenges to using CFRP for structural applications is developing and characterizing a robust joining technique for CFRP to metal sheets. Self-piercing rivet (SPR) has emerged as an economical and viable joining technique and is successfully used by the automotive industry in joining aluminum sheets. In this paper, the tensile and fatigue properties of continuous braided fiber CFRP to AA6011-T82 lap-shear SPRs are presented for joints produced with rivet head heights at two values within the nominal range. Even within the narrow range of head heights considered “nominal”, the rivet head piercing was found to have a dominant effect on both the tensile and fatigue properties of the lap-shear SPR joints.
2017-03-28
Technical Paper
2017-01-0499
Mingde Ding, Jiancai Liu PhD, Jianbo Su Sr, Zhiyuan He Sr, Benhong Tan Sr, Ligang Wang
Recently, for automotive industry, weight reduction is increasingly needed to improve fuel efficiency and to meet emission requirement. Substituting heavy metallic materials with strong and light composites seems to be the most viable choice to achieve vehicle weight reduction. Because of a high level of styling flexibility and simple process, injection molding is the concern of OEMS. However, injection molding part especially for large part would have large deformation. Therefore, the deformation must be controlled within the requirement during development. According with topology optimization result, we get the structure of IP carrier. The result of moldflow analysis showed that the largest deformation in X direction is 19.4mm, in Y direction is 9.5mm, in Z direction is 13.7mm, which were not satisfy the deformation requirement that was the deformation of the core area must be less than 3mm. By structure optimization, the deformation reduction was obviously.
2017-03-28
Technical Paper
2017-01-0536
William Goodwin, Claudio Mancuso, Nicolas Brown
The development of automotive embedded software and calibrations presently involves an expensive development cycle in terms of both time and cost. A primary reason is the associated expense and time require to apply the various technologies needed for software testing and calibration development. Early in the design cycle software-in-the-loop (SIL) and Hardware-in-the-Loop (HIL) systems are typically employed. Later stages use costly engine and vehicle hardware as part of the software test and calibration development process. During this phase propulsions systems may initially utilize dynamometers and eventually migrate to vehicle level testing. All these technologies contribute to large budgets and design times required for embedded software and calibration development.
2017-03-28
Journal Article
2017-01-0266
Shervin Shoai Naini, Junkui (Allen) Huang, Richard Miller, John R. Wagner, Denise Rizzo, Scott Shurin, Katherine Sebeck
Designing an efficient cooling system with low power consumption is of high interest in the automotive engineering community. Heat generated due to the propulsion system and the on-board electronics in ground vehicles must be dissipated to avoid peak component heat loads. In addition, proper thermal management will offer improved system durability and efficiency while providing a flexible, modular, and reduced weight structure. Traditional cooling systems are effective but they typically require high energy consumption which provides motivation for a paradigm shift. This study will examine the integration of passive heat rejection pathways in ground vehicle cooling systems using a thermal bus. Potential solutions include heat pipes and composite fibers with high thermal properties and light weight properties to move heat from the source to ambient surroundings.
2017-03-28
Technical Paper
2017-01-0301
Lu Huang, Ming Shi
Forming limit curve (FLC) is a useful tool to characterize the formability of sheet metals. It can be used as a failure criterion in a laboratory setting or computer simulation for forming/stamping studies and in actual production in a press shop to assess the formability severity. Digital image correlation (DIC) technique has been proved as a potent tool to determine the FLC of sheet metals. Despite of its rising popularity, one of the major technical challenges using the DIC to generate FLC is to accurately pinpoint the onset of localized necking based on DIC data analysis. In addition to the commonly applied ISO 12004-2 standard, a plethora of DIC data analysis approaches have been developed. In this study, five different approaches have been practiced to determine the limit strains at the onset of localized necking, including: ISO12004-2 standard, second derivative, gliding correlation coefficient, linear best fit, and curvature assisted necking zone methods.
Viewing 1 to 30 of 3958