Criteria

Text:
Sector:
Display:

Results

Viewing 331 to 360 of 86944
2018-04-03
Technical Paper
2018-01-0116
Chien-Po Huang, Wei-Ning Chen, Shin-Jang Sung, Jwo Pan
Effects of impact velocity on the compressive behavior of representative volume element (RVE) specimens of lithium-ion battery modules are investigated by experiments and computations. An impact test machine using pressurized nitrogen was designed to perform impact tests of module RVE specimens. The experimental results show the effects of impact velocity on the compressive behavior of module RVE specimens. The experimental results also show the physical mechanisms of module RVE specimens under dynamic loading conditions. Computational models are also developed for simulations of module RVE specimens under dynamic loading conditions. The computational results show that the computational models can be used to simulate the load-displacement curves of module RVE specimens under dynamic loading conditions.
2018-04-03
Technical Paper
2018-01-0117
Paul McKune, Alex Khutorsky, Kapil Butala
Press hardenable ultra high strength steel (UHSS) is commonly used for automotive components to meet crash requirements with minimal mass addition to the vehicle. Press hardenable steel (PHS) is capable of forming complex geometry with deep sections since the forming takes place at elevated temperatures up to 900 degrees C (in the Austenitic phase). This forming process is known as hot-stamping. The most commonly used PHS grade is often referred to as PHS1500. After hot-stamping, it is typically required to have a yield strength greater than 950 MPa and a tensile strength greater than 1300 MPa. Most automotive design and material engineers are familiar with PHS, the hot-stamping process, and their capabilities. What is less known is the capability of 3rd generation advanced high strength steels (AHSS) which are cold stamped, also capable of forming complex geometry, and are now in the process of, or have recently completed, qualification at most automotive manufacturers.
2018-04-03
Technical Paper
2018-01-0118
Qiang Gao, Yuanlong wang, Zheng-Dong Ma, Hong Zhong
The double-V honeycombs (DVH) are a type of auxetic materials showing the negative Poisson’s ratio which can contract under compression different from the conventional materials. Due to the unique properties, it can have higher stiffness and better impact resistance with light weight. In this paper, a cylindrical honeycomb tube based on the double-V unit structure is proposed. First, the nominal Poisson’s ration, Young’s module in the longitudinal and circumferential directions and radial compliance are derived analytically. Also, the thickness in radial direction of the DVH honeycomb tube on these mechanical properties are analyzed. Second, the finite element(FE) method is utilized to obtain the numerical solutions and verify the accuracy of the analytical solutions. The results show that there is a good agreement between the results obtained by the two methods.
2018-04-03
Technical Paper
2018-01-0119
xian Wu, Shuxian Zhang, Jianwang Shao
The metallic NPR metamaterials designed in this study are based on re-entrant lattice structures. Re-entrant structures are known to be one main class of auxetic structures that display negative Possion’s ratio, which can be manufactured by 3D printing technology. This kind of metamaterial has good designability. We can change its overall mechanical properties by changing its geometric parameters. In order to achieve better impact performance, the structure can be designed into some gradient types. The mechanical properties of different gradient structures under the same impact conditions were compared to find the proper gradient structures. On the other hand, the impact performance can also be changed by the impact conditions. The initial impact velocity was changed to study the effect of impact conditions on the mechanical properties of the gradient structure. Based on the studies, we applied the lattice structure to the automobile energy absorbing box.
2018-04-03
Technical Paper
2018-01-0105
Victor Li, Yulong Ge, Sai Guo, Zhengliang Su, Yong Xia
In recent years, structural adhesives have rapidly become the preferred alternative to resistance spot welding in fabricating stronger, lighter aluminum connections. These joints inevitably undergo and must withstand complex quasi-static and/or dynamic loads during their operating lifetime. Therefore, understanding how loading conditions affect the mechanical behavior of adhesive joints is vital to the advancement of structural safety and is worthy of thorough study. Quasi-static and dynamic tests are performed to analyze both the strength and failure mode of aluminum 6062 substrates bonded by adhesives (Darbond EP-1506) at different loading conditions. An Arcan test device, which allows for the application of mixed mode loads ranging from pure peel (Mode I) to pure shear (Mode II) to the adhesive layer, is employed in quasi-static testing. A self-designed, servo-hydraulic medium speed test machine is utilized to perform dynamic testing.
2018-04-03
Technical Paper
2018-01-0107
Xiaoming Chen, Guofei Chen, Lu Huang
Advanced high strength steels (AHSS), due to their significantly higher strength than the conventional high strength steels, are increasingly used in the automotive industry to meet future safety and fuel economy requirements. Unlike conventional steels, the properties of AHSS can vary significantly due to the different steel making processes and their fracture behaviors should be characterized. In the crash analysis, a fracture model is often integrated in the crash simulations to predict fracture during crash events. In this paper, crash simulations including a fracture criterion are conducted for a third generation AHSS i.e., 980GEN3. A generalized incremental stress state dependent damage model (GISSMO) in LS-Dyna is employed to evaluate the fracture predictability in the crash simulation.
2018-04-03
Technical Paper
2018-01-0106
Saurabh Sharma
Improved infrastructure is creating a demand of more trucks on road . On the other hand drivers and owners are becoming demanding and quality conscious. Exteriors are the face of any commercial vehicle which makes the first impression. Robustness is an important criterion in defining exteriors as truck is prone to different accidents and dashes in construction sites. Exterior with metal parts is the basic need which a customer always demands. Tooling of metal parts is too costly and it is always viable goes with high volumes for OEM’s. An alternative which is popular for the same is SMC composite but it is feasible in low volumes and not a durable composite during hitting and cracks are generated which leads to a huge part cost to customer. There are drawback of metal also as it is more in weight and also a good amount of money spent by customer in repairing metal parts.
2018-04-03
Technical Paper
2018-01-0109
Nao Sugimoto, Naoki Takaki, Kenji Takada
Demands are increasing for the reduction of vehicle weight to enhance automobile fuel efficiency and driving performance, with the use of aluminum alloys expected to help. High-strength aluminum alloys (6xxx series, 7xxx series) are called for to enhance crash safety performance, and the prediction of material fracture is a key factor in the application of these alloys. This research presents a FEM model that can predict both tensile fracture and bending fracture when large deformations occur in the extrusion direction of high-strength aluminum alloy extrusion. The fracture characteristics of high-strength aluminum alloy extrusion were obtained by tensile and bending tests, and the factors governing ductile performance were clarified. Fracture was defined in the FEM model using the Cockcroft-Latham ductile fracture model.
2018-04-03
Technical Paper
2018-01-0111
Tim Reaburn
An Ultralight Weight Door (ULWD) has been developed that is 40% lighter than a baseline 2016 mid-size vehicle’s driver side door. The ULWD scope encompasses the entire door, including the door-in-white (DIW), interior trim, glazing, hardware, wiring, etc. To achieve such a substantial mass reduction while still meeting the baseline vehicle’s performance metrics (including safety, durability, NVH, appearance, etc.) at a minimal cost increase, the door design relies on a comprehensive full system approach that includes a unique architecture in addition to lightweight materials and components. To optimize the strength and weight of the ULWD, a new aluminum intensive DIW architecture construction was developed. The new structure features 5000 series and 6000 series aluminum stamped panels, aluminum vacuum die cast, and warm formed 7000 series aluminum door beam.
2018-04-03
Technical Paper
2018-01-0108
Zhexin Pan, Puying Zhao, Xinqi Wei, Huili YU
Metal foil is a widely-used material in the automobile industry, of which the honeycomb barriers is made, and used as current collectors in Li-ion batteries. Plenty of studies proved that the metal foil is quite different from the metal sheet because of the size effect on microscopic scale, as the metal foil shows a larger fracture stress and a lower ductility than the metal sheet. While, the fracture behavior and accurate constitutive model of metal foil with the consideration of the strain rate effect are widely concerned in further studies of battery safety and the honeycomb. This paper has conducted experiments on 3 aluminum foil of different thickness, exploring the quasi-static and dynamic micro-tensile testing method and the anisotropy mechanical behavior for the very thin foil. Two metal foil dog-bone specimens and a bunch of notched specimens are tested fulfilling the range of strain rates from 2×〖10〗^(-4)/s to 40/s and various stress states.
2018-04-03
Technical Paper
2018-01-0097
Henry Guo, Wenchuan Jia, Farid Ahdad
Rotor failure in housings at high rotational speed is a critical event in the automotive and aerospace industry. The design of the containment housing that encloses the rotor burst is important to ensure the safety of the surrounding area. It is essential to perform rotor containment testing and numerical simulation study. This paper first presents the results of a series of regular disk with same geometry and tube with different thickness containment testing. The disk is made of nickel base alloy and the tube is made of high silicon molybdenum (HiSiMo) ductile iron. The regular disk is released at certain rotating speed which subsequently impacts the inner wall of the tube with uniform thickness. Three groups of tests are conducted at the high speed rotor spin testing facility in the laboratory with different disk rotating speed and tube thickness. Then numerical simulations are carried out using nonlinear finite element method to repeat and study the impact process.
2018-04-03
Technical Paper
2018-01-0110
Stephen Roper, Daozhong Li, Vlad Florea, Christopher Woischwill, Il Yong Kim
The automotive industry is facing significant challenges for next-generation vehicle design as fuel economy regulations and tailpipe emission standards continue to strive for greater efficiency. In order to ensure vehicle design reaches these sustainability targets, lightweighting through multi-material design and topology optimization (TO) has been suggested as the leading method to reduce weight from conventional component and small assembly structures. More effective tools, techniques, and methodologies are now required to advance the development of multi-phase optimization tools beyond current commercial capability, and help automotive designers achieve critical efficiency improvements without sacrificing performance. Presented here is a unique tool description and practical application of multi-material topology optimization (MMTO), a direct extension of the classical single-material problem statement (SMTO).
2018-04-03
Technical Paper
2018-01-0096
Guowei zhou, Qingping Sun, Danielle Zeng, Dayong Li, Xuming Su
Dynamic 3-point bending test and axial crush test are performed on carbon fiber reinforced plastic (CFRP) composite components. The energy absorptions of unidirectional (UD) and woven fabric composites with different layups are compared at various impact velocities. The experimental results show delamination is one of the key failure modes. Without considering delamination in simulation, the predicted results are away from the experimental ones both in loading curve and failure phenomenon. With simple assumption of delamination, the simulation with MAT 54 and 58 in Lsdyna shows good agreement with the experimental ones.
2018-04-03
Technical Paper
2018-01-0099
Sujit Mohire, Pravin kathale, Mithun Chaskar, Vishveshvar Tendulkar
Drive components of live axle undergoes different loading conditions during field usage depending upon terrain conditions, vehicle loading and traffic conditions etc. Drive components experiences loading in terms of different torque levels while running on vehicle. Testing of these drive components of axle on test rig for endurance life is an imperative part of axle development, owing to limitations of vehicle testing on account of time and cost involved. Similarly, correlating field failures with rig testing is equally critical. In such situation, if a test cycle is derived correlating the field usage, rig testing can be effectively used for durability and reliability testing. To bridge this gap, an approach is presented in this paper wherein test cycle is derived based on the data collected on vehicle in the field under service road and loading conditions.
2018-04-03
Technical Paper
2018-01-0098
Zhangxing Chen, Manlin Wang, Yimin Shao, Qingping Sun, Haibin Tang, Hongyi Xu, Katherine Avery, Danielle Zeng, Xuming Su
Chopped carbon fiber sheet molding compound(SMC) material is a promising candidate for mass-production vehicle components. However, the experimental characterization of SMC material property is still a challenging task and needs to be further investigated. There now exists two ASTM standards (ASTM D7078/D7078M and ASTM D5379/D5379M) for characterizing the shear properties of composite materials. However, which standard is suitable for SMC material characterization is still unknown. To find out a suitable way for characterize the shear property of SMC material, Digital Image Correlation(DIC) shear tests according to two standards are conducted separately to make a comparison. The results show that none of the test samples according to ASTM are valid. Moreover, the failure mode of these samples indicate that the failure is caused by the additional moment raised by the improper design of the fixture.
2018-04-03
Technical Paper
2018-01-0103
J.P. Weiler, G. Wang, R. Berkmortel
Historically, accelerated cyclic corrosion test protocols utilized by OEM’s have been developed based on a great knowledge and abundant vehicle field-data of primarily steel-containing vehicle components. Laboratory accelerated cyclic corrosion tests with repeated cycles of wet, dry, humid, and / or corrosive media application have been developed both separately, and in partnerships, such as in the case of SAE J2334, to simulate a severe corrosive field environment for evaluation of cosmetic corrosion performance of painted steel. With the interest in lightweight metals such as Aluminum and Magnesium in automotive applications, the validity and confidence of these accelerated test protocols with vehicle field data of lightweight metals is valuable to further increasing the usage of these metals. Over the last several years, Meridian has completed a long-term assessment of the corrosion performance of as-cast and powder coated die-cast magnesium in an underbody vehicular environment.
2018-04-03
Technical Paper
2018-01-0102
Dong Young LEE, Seok Ha
As environmental problems such as global warming are emerging, regulations on automobile exhaust gas are strengthened and various exhaust gas reduction technologies are being developed in various countries in order to satisfy exhaust emission regulations. EGR (exhaust gas recirculation) technology is a very effective way to reduce nitrogen oxides at high combustion temperatures by using EGR coolers to lower the combustion temperature. This EGR cooler has been mass-produced in stainless steel, but it is expensive and heavy. Recently, high efficiency and compactness are required for the EGR cooler to meet the new emission regulation. If aluminum material is applied to the EGR cooler, heat transfer efficiency and light weight can be improved due to high heat transfer coefficient of aluminum compared to conventional stainless steel, but durability is insufficient. In order to obtain enhanced performance and durability of EGR cooler, 5-layer aluminum clad material is developed.
2018-04-03
Technical Paper
2018-01-0154
Prashant kumar, Sameer Srivastava, Arnab Sandilya, Kapil Kumar Pandey, Pavan pabba
Increasing customer expectations of comfort and convenience inside the vehicle has resulted in OEMs working on various solutions to improve interior ergonomics and overall layout. One of the key areas of focus has been the ease of ingress into and egress from the vehicle. But with increased sharing of platforms in OEM Model Lineup, due to obvious benefits like cost and common tooling/parts, it is very difficult to achieve improved results in different vehicles(like Hatchback, Notchback, SUV etc.) but with same underpinnings. In such a scenario, one of the commonly used approaches is provision of false flooring for front / Rear Passengers for easy Egress-Ingress. Various materials like Synthetic felts, PU foam blocks, Rubber blocks, expanded polypropylene etc. are used to this end. Of the various requirements, any solution for this application, compressive strength is a key requirement.
2018-04-03
Technical Paper
2018-01-0155
Max Sardou
SARDOU SAS has developed highly stressed composites parts for 36 years. SARDOU SAS and QUALITY INDUSTRIAL PRODUCT jointly invented and patented composite “C” springs in 1993. We have designed and tested ultra-performance “C” springs, giving an incredible energy density of 1350 joules per kilogram (compared to 300 for steel springs). This energy density means a potential 78% weight savings! But in the last century, weight savings was not a must and platform personnel were reluctant to use anything else than coil springs. So in 2002, in order to comply with the wishes of platform personnel, we have invented and developed composite coils springs. Composite coils springs are the best choice for McPherson suspensions. We have identified that the weak point, in composite coils springs, is its epoxy matrix. During heavy loading, the matrix undergoes micro cracking. Then, during repeated loadings, micro cracks propagate and merge, transforming the matrix into a fine powder.
2018-04-03
Technical Paper
2018-01-0152
Luke Ryan, Jonathan Wong, Ryan Pitre, Michele Faragalli, Il Yong Kim
The presence of engineering plastics in the automotive, aerospace, and defense industries is rapidly increasing: the lightweight and cost-effective nature of these materials, coupled with improvements to their mechanical performance, is driving the replacement of more traditional materials. However, the stiffness of engineering plastics cannot rival that of their metal counterparts, making metal replacement challenging in cases where stiffness is paramount. Nanometal-polymer hybrids, which are engineering plastics reinforced by a thin high-strength metal coating, provide an innovative solution to this problem. However, implementing this hybrid material into innovative designs remains a challenge, as relatively little information about mechanical behaviour or appropriate modeling techniques for this complex material are available. In this article, an efficient and effective finite element modeling approach for the structural analysis of nanometal-polymer hybrids is presented.
2018-04-03
Technical Paper
2018-01-0153
Karthik Govindaraj, Ashish Junankar, Rao Venkateshwara, Vijay Papanal
This paper describes modified polypropylene copolymer (PPCP) material for thin wall front bumper development (2.5 mm) with integrated grill in automotive application. This compounded PPCP material has optimized flow behavior, tensile strength, modulus, impact strength, and thermal properties to meet the functional requirements. This is a ready to mold material used in injection molding process. Front bumper and grill are functional components with slow speed impact requirement to absorb impact in real world. These parts have precise fitment requirement under sun load condition. Front bumper is also having other critical criteria with respect to vehicle variants such as aesthetic mold-in-color finish as well as painted finish. Grill has air entry performance criteria to ensure cooling efficiency in intercooler compartment.
2018-04-03
Technical Paper
2018-01-0158
Evan Freeman-Gibb, Jennifer Johrendt, O. Remus Tutunea-Fatan
Carbon fiber SMC (sheet molding compound) is an attractive material for automotive lightweighting applications, but several issues present themselves when adapting a process developed for glass fiber composites to instead use carbon fibers. SMC is a discontinuous fiber material, so individual carbon fiber tows must be chopped into uniform rovings before being compounded with the resin matrix. Rotary chopping is one such method for producing rovings, but high wear rates are seen when cutting carbon fibers. Experiments were performed to investigate the wear progression of cutting blades during rotary carbon fiber chopping. A small rotary chopper with a polyurethane backing and thin, hardened steel blades was used to perform extended wear tests (120; 000 chops, or until failure to reliably chop tows) to simulate the lifespan of blades during composite material production.
2018-04-03
Technical Paper
2018-01-0159
Masaaki Nishi
Global warming continues to advance, so carbon reduction is a key issue and enhancement of fuel efficiency is an important mission for the automotive industry. Against this background, reduction of body component material weight leads to engine and body downsizing and reduction of body aerodynamic drag, which makes it an effective means of enhancing fuel efficiency. To achieve this weight reduction, various universities, research institutions, and companies are actively pursuing research on multimaterial fabrication technology using lightweight materials in a composite manner. Among these efforts, particular attention is being given to research on carbon fiber reinforced epoxy resin (CFRP), but there are still many unclear points in regards to cost, manufacturing methods, and assurance, which pose issues for application by simple material substitution.
2018-04-03
Technical Paper
2018-01-0157
Karthik Govindaraj, A RAJKUMAR, RAMADAS NARAYANAN, SUNKARA NARENDRABABU, VENKATESAN D
This paper describes modified polypropylene copolymer (PPCP) material for canopy plastic structure in a modular commercial passenger vehicle. This compounded PPCP material has optimized flow behavior, tensile strength, modulus, impact strength, and thermal properties to meet the functional requirements. Material described in this paper is a PPCP compound reinforced with glass fiber and mica filler. The application described in this paper is a canopy plastic structure, which is a structural exterior plastic part. Canopy plastic structure acts as a structural frame to hold vinyl canopy in both sides and tail gate of vehicle. In this paper, PPCP has been explored for canopy plastic structure part against conventional polyamides. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analyzed by using mold flow analysis.
2018-04-03
Technical Paper
2018-01-0146
Shuming Chen
This paper studies a multi-objective optimization design of interior noise for an automotive body. In order to predict the interior noise, an acoustic-structure coupled model with materials and properties was established based on a passenger car. Moreover, three kinds of approximation models related damping thickness and the root mean square of the driver's ear sound pressure level were established through Latin hypercube method and the corresponding experiments. The prediction accuracy was analyzed and compared for the approximate response surface model, Kriging model and Radial Basis Function neural network model. On this basis, multi-objective optimization of the vehicle interior noise was conducted by using NSGA-II. According to the optimization results, the damping composite structure was applied on the car body structure. Then, the comparison of sound pressure level response at driver's ear location before and after optimization was made under the different conditions.
2018-04-03
Technical Paper
2018-01-0147
Wang Wenzhu, Liu Gang, Cheng Mianhong
Aiming at the rear disc brake squeal for an SUV, the finite element model (FEM) of contact coupling of disc brake was established by using finite element software. The validity of the FEM is verified by the experimental modal analysis method. The complex modal analysis method was used to analyze the unstable modes of the system under two kinds of friction coefficients. In order to solve the problem of brake squeal, the method of sticking silencing sheet on the brake block backboard was adopted in which the damping of the silencer. In the simulation, the damping of the silencing sheet is described by Rayleigh damping. The simulation results show that the silencing sheet can effectively suppress brake squeal and improve the stability of the system.
2018-04-03
Technical Paper
2018-01-0144
Wenlong Yang, Michael Dinsmore, Alexis Castel, Ricardo Alvarez, Roger Michna
Porous materials have been applied increasingly for absorbing noise energy and improving the acoustic performance. To predict the performance of these materials, different models have been proposed and much progress has been achieved. However, most of the foregoing researches were conducted on single porous material. In real application, porous materials are usually combined with other kinds of materials to compose a multilayered noise control treatment. This paper investigates the acoustic performance of such treatments with a combination of porous and non-porous media. Results from numerical simulation are compared to experimental measurements. Transfer matrix method is adopted to simulate the insertion loss and absorption associated with three samples of a noise control treatment product, which has two porous layers bonded by an impervious screen. The elastic parameters of the foam solid phase are estimated by matching the simulated results to the tested data.
2018-04-03
Technical Paper
2018-01-0145
Urban Rönnqvist, Janos Ribarits
Today’s trend of downsized internal combustion engine development for cars is characterized with; high torque, low engine speed, low weight, high degree of cyclic irregularity, low excitation frequency due to fewer cylinders active e.g. 4-cylinder or less. Torque output 100 Nm at low engine speed 1000 rpm has become normal. This implies in respect of vibrations that it is important to control engine suspension rigid body modes e.g. roll yaw and pith ones. The rigid body modes frequencies should be low so they cannot be reached and induced by the low exciting harmonics of cylinder pressure and mass forces for low engine speeds or idling. Crucial is the rigid body modes in relation to the excitation forces. It is also important to control the overall flexible vibration modes.
2018-04-03
Technical Paper
2018-01-0150
Max Sardou
SARDOU SAS has developed highly stressed composites parts for 36 years. SARDOU SAS and QUALITY INDUSTRIAL PRODUCT jointly invented and patented composite “C” springs in 1993. We have designed and tested ultra-performance “C” springs, giving an incredible energy density of 1350 joules per kilogram (compared to 300 for steel springs). This energy density means a potential 78% weight savings! But in the last century, weight savings was not a must and platform personnel were reluctant to use anything else than coil springs. So in 2002, in order to comply with the wishes of platform personnel, we have invented and developed composite coils springs. Composite coils springs are the best choice for McPherson suspensions. We have identified that the weak point, in composite coils springs, is its epoxy matrix. During heavy loading, the matrix undergoes micro cracking. Then, during repeated loadings, micro cracks propagate and merge, transforming the matrix into a fine powder.
2018-04-03
Technical Paper
2018-01-0148
Ravi (S. T.) Raveendra
A widely-used procedure for the solution of high frequency vibroacoustic problems is statistical energy analysis (SEA). Statistical energy analysis is a lumped parameter approach that treats a buildup system as a collection of subsystems with average properties. While the SEA has found wide acceptance, the approach does not provide any information about the spatial variation of the dynamic response within a subsystem. Integral equations are well suited as a post processing tool to evaluate sound field within a domain using energy density and intensity at the surface of the domain. In the present work, energy flow integral equations are extended to post-process SEA results to predict interior sound field at desired locations.
Viewing 331 to 360 of 86944