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Viewing 31 to 60 of 8950
2017-03-28
Technical Paper
2017-01-0314
Lu Huang, Ming Shi, Patrick Russell
Abstract Fracture strain data provide essential information for material selection and serve as an important failure criterion in computer simulations of crash events. Traditionally, the fracture strain was measured by evaluating the thinning at fracture using tools such as a microscope or a point micrometer. In the recent decades, digital image correlation (DIC) has evolved as an advanced optical technique to record full-field strain history of materials during deformation. Using this technique, a complete set of the fracture strains (including major, minor, and thickness strains) can be approximated for the material. However, results directly obtained from the DIC can be dependent on the experiment setup and evaluation parameters, which potentially introduce errors to the reported values.
2017-03-28
Technical Paper
2017-01-0311
Pedro Stemler, Anoop Samant, Dennis Hofmann, Taylan Altan
Abstract The capabilities of the servo press for varying the ram speed during stroke and for adjusting the stroke length are well known. Various companies installed servo presses for blanking. Some of the considerations may include increase in productivity and flexibility in adjusting the ram stroke, noise reduction and improvement of edge quality of blanked edge. The objectives of this study are to determine the effect of ram (blanking) speed upon the edge quality, and the effect of multiple step blanking using several punch motions, during one blanking stroke.
2017-03-28
Technical Paper
2017-01-0312
ZiQiang Sheng, Pankaj Mallick
Abstract Based on findings from micromechanical studies, a Ductile Failure Criterion (DFC) was proposed. The proposed DFC treats localized necking as failure and critical damage as a function of strain path and initial sheet thickness. Under linear strain path assumption, a method to predict Forming Limit Curve (FLC) is derived from this DFC. With the help of predetermined effect functions, the method only needs a calibration at uniaxial tension. The approach was validated by predicting FLCs for sixteen different aluminum and steel sheet metal materials. Comparison shows that the prediction matches quite well with experimental observations in most cases.
2017-03-28
Technical Paper
2017-01-0309
Mitchell Rencheck, Paul Zelenak, Jianhui Shang, Hyunok Kim
Abstract Aluminum alloys are increasingly utilized in automotive body panels and crash components to reduce weight. Accurately assessing formability of the sheet metal can reduce design iteration and tooling tryouts to obtain the desired geometry in aluminum stampings. The current ISO forming limit curve (FLC) procedure is a position dependent technique which produces the FLC based on extrapolation at the crack location. As aluminum sheet metal use increases in manufacturing, accurate determination of the forming limits of this material will be necessary prior to production. New time dependent methods using digital imaging correlation (DIC) account for variations in material behavior by continuously collecting strain data through the material necking point. This allows more accurate FLC determination that is necessary for efficient design in the automotive stamping industry.
2017-03-28
Journal Article
2017-01-0310
Wei Wu, Dajun Zhou, Donald Adamski, Darryl Young, Yu-Wei Wang
Abstract The die wear up to 80,800 hits on a prog-die setup for bare DP1180 steel was investigated in real production condition. In total, 31 die inserts with the combination of 11 die materials and 9 coatings were evaluated. The analytical results of die service life for each insert were provided by examining the evolution of surface wear on inserts and formed parts. The moments of appearance of die defects, propagation of die defects, and catastrophic failure were determined. Moreover, the surface roughness of the formed parts for each die insert was characterized using Wyko NT110 machine. The objectives of the current study are to evaluate the die durability of various tooling materials and coatings for flange operations on bare DP 1180 steel and update OEM tooling standards based on the experimental results. The current study provides the guidance for the die material and coating selections in large volume production for next generation AHSSs.
2017-03-28
Technical Paper
2017-01-0307
Xiaohua Hu, Xin Sun, Sergey Golovashchenko
Abstract The hole stretchability of two Aluminum Alloys (AA6111 and AA6022) are studied by using a two stages integrated finite element framework where the edge geometry and edge damages from the hole piercing processes were considered in the subsequent hole expansion processes. Experimentally it has been found that AA6022 has higher hole expansion ratios than those of AA6111. This observation has been nicely captured by finite element simulations. The main cause of differences have been identified to the volume fractions of the random distributed second phase hard particles which play a critical role in determining the fracture strains of the materials.
2017-03-28
Technical Paper
2017-01-0308
Hyunok Kim, Jianhui Shang, James Dykeman, Anoop Samant, Clifford Hoschouer
Abstract Practical evaluation and accurate prediction of edge cracking are challenging issues in stamping AHSS for automotive body structures. This paper introduces a new hole-expansion testing method that could be more relevant to the edge cracking problem observed in stamping AHSS. A new testing method adopted a large hole diameter of 75 mm compared to the ISO standard hole diameter of 10 mm. A larger hole diameter was determined to be sensitive to edge cracking using the finite element method (FEM) based sensitivity analyses with various hole sizes. A die punching tool was developed to replicate typical production blanking conditions. An inline monitoring system was developed to visually monitor the hole edge cracking during the test and synchronize with the load-displacement data. Two AHSS materials, DP980 and TRIP780, and an aluminum alloy, A1 5182-O, were experimentally evaluated.
2017-03-28
Technical Paper
2017-01-1732
Payodh Dwivedi
Abstract The conventional hybrid engine faces one major problem i.e. high cost of production. Although hybrid engines, in many sense proved to be highly efficient and environmental friendly, but high cost of production makes them less feasible and limits their applications. This problem is overcome by a new design in which instead of having Internal Combustion(IC) engine and electric motor separately, these two are incorporated under same housing. This involves a different working mechanism of electric motor which is as described below- This mechanism is applied to a normal engine which has two or more than two cylinders in any configuration or orientation. Taking example of In-line four cylinder engines as it is most widely used. In this the two cylinders work on conventional internal combustion mechanism, but the other two cylinders are electric cylinder and works on electricity.
2017-03-28
Technical Paper
2017-01-1726
Sameer Shah, Aayoush Sharma, Raghav Angra, Nitin Singh, Khalique Ahmed
Abstract In an unavoidable event of a suspect being chased by police, there is high probability for the criminal to evade the police while driving his vehicle. At many instances, criminal escapes without leaving a trail behind and becomes untraceable. A new concept of Vigilance Assistance System Network (VASN) has been developed, which is spread across the city and helps in catching the escaping criminals. At every junction, the traffic-signals are installed with a microcontroller chip and these connected traffic signals form a network with distinct city areas demarcated on the map. The vehicle is installed with GPS and a RFID module on their ECU when it approaches any intersection or junction; they receive wireless signals from traffic-signals and transmit another registering signal to the traffic-light wirelessly through RFID.
2017-03-28
Technical Paper
2017-01-1703
Ryan A. Howell, Richard Gerth
Abstract Fe-Mn-Al-C steel alloys have been previously studied for their potential as an alternative steel alloy for Rolled Homogeneous Armor (RHA). Prior examination of the material system has shown promise in this capacity due to the high strength and reduced density of Mn steels as compared to RHA. The prior tested materials were both wrought and cast versions but were all less than an inch in thickness. The alloy is once again being examined, but this time in thicker wrought plate. The aim of the current body of work is to develop a Military Specification (MIL-SPEC) for this new class of ballistically capable material. For industry and communities interested in such material development, the purpose of this paper, then, is to provide a summary of the processing parameters, the prior ballistic and dynamic material testing, cutting and welding approaches, and the extent of progress on industrial sized thick plate development.
2017-03-28
Technical Paper
2017-01-1704
D.J. Branagan, A.E. Frerichs, B.E. Meacham, S. Cheng, A.V. Sergueeva
Abstract Automotive OEMs are compelled by increasingly stringent global emissions standards to find economic solutions for building higher efficiency vehicles without compromising safety and ride quality. This challenge requires new advanced high strength steels (AHSS) that will significantly reduce vehicle weight and improve fuel economy. In addition to providing higher strength, these automotive sheet steels must have exceptional formability to produce reduced gauge parts with increasingly complex geometries. Formability is comprised of two components, global and local. Global formability represents the ability of a sheet material to be deformed under various stress conditions and to be formed into a part without failure. It can be estimated using forming-limit diagrams or ductility measurements from conventional uniaxial tensile tests. However, these tests cannot reliably assess the local formability at the edges or at the internal holes of the blanks during stamping.
2017-03-28
Technical Paper
2017-01-1700
Rebekah L. Houser, Willett Kempton, Rodney McGee, Fouad Kiamilev, Nick Waite
Abstract Electric vehicles (EVs) hold the potential to greatly shape the way the electric power grid functions. As a load, EVs can be managed to prevent overloads on the electric power system. EVs with bidirectional power flow (V2G) can provide a wide range of services, including load balancing, and can be used to increase integration of renewable resources into electric power markets. Realizing the potential of EVs requires more advanced communication than the technology that is in wide use. Common charging standards do not include a means for an EV to send key vehicle characteristics such as maximum charge rate or battery capacity to a charging station and thus to the grid.
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
Journal Article
2017-01-1705
Hua-Chu Shih, Dajun Zhou, Bruce Konopinski
Abstract The hole piercing process is a simple but important task in manufacturing processes. The quality requirement of the pierced hole varies between different applications. It can be either the size or the edge quality of the hole. Furthermore, the pierced hole is often subject to a secondary forming process, in which the edge stretchability is of a main concern. The recently developed advanced high strength steels (AHSS) and ultra high strength steels (UHSS) have been widely used for vehicle weight reduction and safety performance improvements. Due to the higher strength nature of these specially developed sheet steels, the hole piercing conditions are more extreme and challenging, and the quality of the pierced hole can be critical due to their relatively lower edge stretching limits than those for the conventional low and medium strength steels.
2017-03-28
Technical Paper
2017-01-1706
Sandeep Bhattacharya, Daniel Green, Raj Sohmshetty, Ahmet Alpas
Abstract Automobile body panels made from advanced high strength steel (AHSS) provide high strength-to-mass ratio and thus AHSS are important for automotive light-weighting strategy. However, in order to increase their use, the significant wear damage that AHSS sheets cause to the trim dies should be reduced. The wear of dies has undesirable consequences including deterioration of trimmed parts' edges. In this research, die wear measurement techniques that consisted of white-light optical interferometry methods supported by large depth-of-field optical microscopy were developed. 1.4 mm-thick DP980-type AHSS sheets were trimmed using dies made from AISI D2 steel. A clearance of 10% of the thickness of the sheets was maintained between the upper and lower dies. The wear of the upper and lower dies was evaluated and material abrasion and chipping were identified as the main damage features at the trim edges.
2017-03-28
Technical Paper
2017-01-1708
Saeid Nasheralahkami, Sergey Golovashchenko, Collin Malek, Erika Rugh, Daniel Kowalsky, Weitian Zhou
Abstract In recent years, dual phase (DP) Advanced High Strength Steels (AHSS) and Ultra High Strength Steels (UHSS) are considered as prominent materials in the automotive industry due to superior structural performance and vehicle weight reduction capabilities. However, these materials are often sensitive to trimmed edge cracking if stretching along sheared edge occurs in such processes as stretch flanging. Another major issue in the trimming of UHSS is tool wear because of higher contact pressures at the interface between cutting tools and sheet metal blank caused by UHSS’s higher flow stresses and the presence of a hard martensitic phase in the microstructure. The objective of the current paper is to study the influence of trimming conditions and tool wear on quality and stretchability of trimmed edge of DP980 steel sheet. For this purpose, mechanically trimmed edges were characterized for DP980 steel and compared with other steels such as HSLA 350 and BH210.
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
2017-01-0468
Raj S. Roychoudhury
Abstract A new weld design to form plastic hollow articles is conceived. Its design is T-shaped such that the joint loading under pressure is no longer in peel but in tension, vertically to the weld surface. This weld design can be easily achieved, overcoming the limitation of die lock in injection molding and by the hot plate weld design adopted for this welding. Test samples were built to evaluate the new weld design concept and hot plates designed to help perform this weld joint. Pull test on the conventional L-shaped and the new T- shaped welded samples show an improvement of about 50% weld strength for the new T-shaped weld design. Hence a weld joint stronger than the parent material, in forming plastic hollow articles, is possible.
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
2017-01-0471
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
2017-01-0474
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
2017-01-0476
Seiji Furusako, Masatoshi Tokunaga, Masanori Yasuyama
Abstract To reduce the weight of automobile bodies, application of high-strength steel sheets is expanding. Furthermore, middle and high carbon steels are expected to be used to lower the environmental impact and cost in the automobile steel sheet industry. However, it is necessary to enhance the joint strength of the steel sheets. In this study, hat-shaped components were made using resistance spot (RS) welding or arc spot (AS) welding on S45C steel sheets (including 0.44% carbon), 1.4 mm thickness and strength of 1180 MPa grade. A dynamic three-point bending test was conducted on the components and their crashworthiness was compared. Some RS welds fractured (separated) during the three-point bending test even though the diameter of the weld metal was increased to 5√t (t means thickness of the sheet); however, AS welds did not fracture.
2017-03-28
Technical Paper
2017-01-0481
Xian Jun Sun, Patricia Tibbenham, Jin Zhou, Danielle Zeng, Shiyao Huang, Li Lu, Xuming Su
Abstract Weld lines occur when melt flow fronts meet during the injection molding of plastic parts. It is important to investigate the weld line because the weld line area can induce potential failure of structural application. In this paper, a weld line factor (W-L factor) was adopted to describe the strength reduction to the ultimate strength due to the appearance of weld line. There were two engineering thermoplastics involved in this study, including one neat PP and one of talc filled PP plastics. The experimental design was used to investigate four main injection molding parameters (melt temperature, mold temperature, injection speed and packing pressure). Both the tensile bar samples with/without weld lines were molded at each process settings. The sample strength was obtained by the tensile tests under two levels of testing speed (5mm/min and 200mm/min) and testing temperatures (room temperature and -30°C).
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
2017-01-0489
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
2017-01-0499
Mingde Ding, Jiancai Liu PhD, Jianbo Su Sr, Zhiyuan He Sr, Benhong Tan Sr, Ligang Wang
Abstract Because of their high specific stiffness and strength, composite materials have been used in the structural of vehicles to provide a competitive advantage of through weight reduction while maintaining or even increasing functionality. Composite materials have been used for IP carrier which forms the skeleton of the cockpit and provides the base architecture off of which IP components are attached and function. Specially, composite materials using injection molding process have been used to develop IP carrier recently, due to high level of styling flexibility by that can achieve high degree integration and simplicity of process. However, for injection part especially for large part would deform largely. Consequently, deformation controlling is very important for large composite part that used injection molding. In this study mold flow analysis was conducted on the composite IP carrier structure which gets from the topology optimization result.
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
Journal Article
2017-01-0315
Yueqian Jia, Yangyang Qiao, Hao Pan, Edmund Chu, Yuanli Bai
Abstract A comprehensive plasticity and fracture model was built for metal sheets with application to metal sheet forming and vehicle crash simulations. The combined Bai-Wierzbicki (BW [1]) and CPB06ex2 [2] (or Yld2000-2D [3]) anisotropic plasticity model was further extended to consider elevated temperature effects in additional to the effect of multiaxial stress states. A fully modularized framework was established to combine isotropic, kinematic, and cross hardening behaviors under non-linear loading conditions. The all strain based modified Mohr-Coulomb (eMMC) fracture model was used to consider material anisotropy and nonlinear strain path. The model has been implemented into Abaqus/Explicit as a user material subroutine (VUMAT). Test results on advanced high strength steels, aluminum alloy sheets and magnesium alloy sheets are used to validate the modeling and testing methodologies. Very good correlation was observed between experimental and simulation results.
2017-03-28
Technical Paper
2017-01-0316
Kiran Mallela, Andrey Ilinich, S Luckey, Danielle Zeng, Yuan Gan
Abstract Aluminum extrusions are used in the automotive industry for body structure applications requiring cross-section design flexibility, high section stiffness, and high strength. Heat-treatable 6xxx series extrusion alloys have typically been used in automotive due to commercial availability, competitive cost, high strength, and impact performance. This paper presents a characterization study of mechanical properties of 6xxx series aluminum extrusions using digital image correlation (DIC). DIC has been used to capture spatial strain distribution and its evolution in time during material deformation. The materials of study were seamless and structural 6061 and 6082 extrusions. The alloys have been tensile tested using an MTS load frame with a dual optical camera system to capture the stereoscopic digital images. Notable results include the differing anisotropy of seamless and structural extrusions, as well as the influence of artificial aging on anisotropy.
2017-03-28
Technical Paper
2017-01-0326
Samuel J. Tomlinson, Martin J D Fisher, Thomas Smith, Kevin Pascal
Abstract When sealing an application with a radial O-ring system design there is a balance that must be struck between O-ring function and the ease of assembly. If design parameters are not properly controlled or considered it is possible to design an O-ring seal that would require assembly insertion forces that exceed acceptable ergonomic practices from a manufacturing standpoint. If designs are released into production with these high insertion forces manufacturing operators will struggle to assemble parts, creating opportunity for potential operator injury due to repetitive strain or CTD. In this study several variables impacting O-ring system insertion forces were tested to quantify the effects. Results were analyzed to identify design controls that could be implemented from an early design phase to optimize both functionality and ease of assembly.
Viewing 31 to 60 of 8950