Criteria

Text:
Topic:
Display:

Results

Viewing 241 to 270 of 15996
2017-03-28
Journal Article
2017-01-0470
Lunyu Zhang, Shin-Jang Sung, Jwo Pan, Xuming Su, Peter Friedman
Abstract Closed-form structural stress solutions are investigated for fatigue life estimations of flow drill screw (FDS) joints in lap-shear specimens of aluminum 6082-T6 sheets with and without clearance hole based on three-dimensional finite element analyses. The closed-form structural stress solutions for rigid inclusions under counter bending, central bending, in-plane shear and in-plane tension are first presented. Three-dimensional finite element analyses of the lap-shear specimens with FDS joints without and with gap (with and without clearance hole) are then presented. The results of the finite element analyses indicate that the closed-form structural stress solutions are quite accurate at the critical locations near the FDS joints in lap-shear specimens without and with gap (with and without clearance hole) for fatigue life predictions.
2017-03-28
Journal Article
2017-01-0452
David A. Stephenson
Abstract Thermally sprayed engine bores require surface preparation prior to coating to ensure adequate adhesion. Mechanical roughening methods produce repeatable surfaces with high adhesion strength and are attractive for high volume production. The currently available mechanical roughening methods are finish boring based processes which require diameter-specific tooling and significant clearance at the bottom of the bore for tool overtravel and retraction. This paper describes a new mechanical roughening method based on circular interpolation. This method uses two tools: a peripheral milling tool, which cuts a series of concentric grooves in the bore wall through interpolation, and a second rotary tool which deforms the grooves to produce an undercut. This method produces equivalent or higher bond strength than current surface preparation methods, and does not require diameter-specific tooling or bottom clearance for tool retraction.
2017-03-28
Journal Article
2017-01-0498
Tomoya Yabu, Shigeto Yasuhara, Masakazu Kashiwagi
Abstract Regulation of automotive CO2 emissions is becoming increasingly stringent throughout the world in response to global warming. For automakers, this means a focus not only on increasing the fuel economy of powertrains, but also on reducing automotive driving resistance. High expectations are held for thermoplastic fiber-reinforced plastics (FRP) for the realization of automotive weight savings while also offering high levels of productivity and recyclability. Thermoplastic FRP crush boxes display a higher level of energy absorption performance than metal (steel, aluminum, etc.) crush boxes. This will contribute to automotive weight savings and improved package design. In the case of automotive front bumper beam systems, it is necessary to realize stable load characteristics irrespective of the use environment. It is therefore necessary to consider the effects of temperature and thermoplastic resin degradation.
2017-03-28
Journal Article
2017-01-0478
Pai-Chen Lin, WeiNing Chen
Abstract Fatigue analysis of swept friction stir clinch (Swept-FSC) joints between 6061-T6 aluminum (Al) and S45C steel (Fe) sheets was conducted through experimental approaches. Before fatigue tests, a parametric study for the probe geometry of FSC tools was conducted in order to eliminate the hook structure inside the joint and improve the mechanical performance of the joint. Then a series of quasi-static and fatigue tests for Al/Fe Swept-FSC joints in lap-shear (LP) and cross-tension (CT) specimens were conducted. The fatigue data were recorded. The fatigue behavior of Al/Fe Swept-FSC joints in LP and CT specimens were examined through optical and scanning electron microscopes. Experimental results indicated that LP specimens have two failure modes, while CT specimens have only one failure mode. The dominant fatigue crack of each failure mode was identified.
2017-03-28
Journal Article
2017-01-0488
Raju Gandikota
Abstract Testing elastomeric materials that undergo large strains pose challenges especially when establishing failure criteria. The failure criterion for composites and polymers based on finite elasticity published by Feng (1) requires testing under uniaxial and biaxial stretching modes. The classic inflation of a circular disk for biaxial stretch mode poses stability and safety challenges. The test can also be sensitive to end constraints resulting in failure of materials at the constraints. Biaxial stretching with a hemispherical punch is explored in this work. The biaxial stretching allows controlled and repeatable testing. It establishes a clear and reliable failure mechanism of the material at the poles. Through a combination of testing and numerical methods, the stretch ratios and its relation to failure have been established. The method greatly simplifies testing and provides reliable data for a failure criterion for elastomers in numerical modeling.
2017-03-28
Technical Paper
2017-01-1002
Daisuke Tanaka, Ryo Uchida, Toru Noda, Andreas Kolbeck, Sebastian Henkel, Yannis Hardalupas, Alexander Taylor, Allen Aradi
Abstract The purpose of this work was to gain a fundamental understanding of which fuel property parameters are responsible for particulate emission characteristics, associated with key intermediate behavior in the engine cylinder such as the fuel film and insufficient mixing. Accordingly, engine tests were carried out using various fuels having different volatility and chemical compositions under different coolant temperature conditions. In addition, a fundamental spray and film visualization analysis was also conducted using a constant volume vessel, assuming the engine test conditions. As for the physical effects, the test results showed that a low volatility fuel displayed high particulate number (PN) emissions when the injection timing was advanced. The fundamental test clearly showed that the amount of fuel film on the impingement plate increased under such operating conditions with a low volatility fuel.
2017-03-28
Technical Paper
2017-01-1074
Xingfu Chen, Todd Brewer, Cagri Sever, Eben Prabhu, Reda Adimi, Carlos Engler-Pinto
Abstract Cylinder head design is a highly challenging task for modern engines, especially for the proliferation of boosted, gasoline direct injection engines (branded EcoBoost® engines by Ford Motor Company). The high power density of these engines results in higher cylinder firing pressures and higher operating temperatures throughout the engine. In addition to the high operating stresses, cylinder heads are normally heat treated to optimize their mechanical properties; residual stresses are generated during heat treatment, which can be detrimental for high-cycle fatigue performance. In this paper, a complete cylinder head high cycle fatigue CAE analysis procedure is demonstrated. First, the heat treatment process is simulated. The transient temperature histories during the quenching process are used to calculate the distribution of the residual stresses, followed by machining simulation, which results in a redistribution of stress.
2017-03-28
Technical Paper
2017-01-0332
Zhengpan Qi, Li Lu, Linh Doan, Bhavani Thota, Danielle Zeng, Xuming Su
Abstract High density polyethylene (HDPE) is widely used in automotive industry applications. When a specimen made of HDPE tested under cyclic loading, the inelastic deformation causes heat generated within the material, resulting in a temperature rise. The specimen temperature would stabilize if heat transfer from specimen surface can balance with the heat generated. Otherwise, the temperature will continue to rise, leading to a thermo assist failure. It is shown in this study that both frequencies and stress levels contribute to the temperature rise. Under service conditions, most of the automotive components experience low cyclic load frequency much less than 1 Hz. However, the frequency is usually set to a higher constant number for different stress levels in current standard fatigue life tests.
2017-03-28
Technical Paper
2017-01-0323
Rosa Radovanovic, Samuel J. Tomlinson
Abstract Press-in-place gasket stability is required to maintain consistent and predictive sealing compression in a sealing joint utilizing a housing groove and a mating component sealing surface. Without proper balance between height of the groove and height of the gasket, the sealing joint can be compromised. Hence, automotive engineers balance design variables with the desire to achieve long term sealability and gasket stability. The percentage of gasket out of groove was varied to study the interactions of this design control and the resultant deviation of gasket centerline to the groove centerline. Finally, an optimal percentage of gasket out of groove is recommended.
2017-03-28
Technical Paper
2017-01-0339
Sandip Datta, Neil Bishop, Karl Sweitzer, Alexander Atkins
Abstract For many automotive systems it is required to calculate both the durability performance of the part and to rule out the possibility of collision of individual components during severe base shake vibration conditions. Advanced frequency domain methods now exist to enable the durability assessment to be undertaken fully in the frequency domain and utilizing the most advanced and efficient analysis tools (refs 1, 2, 3, 4, 5). In recent years new capabilities have been developed which allow hyper-sized models with multiple correlated loadcases to be processed. The most advanced stress processing (eg, complex von-Mises) and fatigue algorithms (eg, Strain-Life) are now included. Furthermore, the previously required assumptions that the loading be stationary, Gaussian and random have been somewhat relaxed. For example, mixed loading like sine on random can now be applied.
2017-03-28
Technical Paper
2017-01-0494
Michael Christian Haverkamp, Anja Moos
Abstract Material authenticity is an important factor for appearance and perceived quality of the vehicle interior. The term authenticity implies ambivalence: For the product designer, it means identification and trueness of the origin of the material. The customers, however, can only access information on the nature of the materials via their own perception of surface features. Thus, the intended authenticity of a material always needs to be conveyed by its surface. Specific cases illustrate the context: 1. The customer touches a part of known matter, but various layers prevent from directly touching the natural material: e.g. leather at the steering wheel, applications of wood. 2. Perception of a thin surface layer indicates authentic material, which is not fulfilled by the whole part: e.g. plastic parts plated with metal. 3.
2017-03-28
Technical Paper
2017-01-0366
Xingyu Liang, Yuesen Wang, Shuhe Huang, Guichun Yang, Lin Tang, Guoqi Cui
Abstract Due to the mechanical forces under static conditions, the engine cylinders cross section will not be a round circle any more once they are installed. The deformation of an engine cylinder causes increasing lubricating oil consumption and abnormal wear, resulting in worse fuel economy and emissions. However, prediction of deformation on a liner has not been made because of the complication of conditions and structure. In this study, a V6-type engine body model was built and meshed with Hypermesh suit software. Then, cylinder deformation under static condition has been simulated and analyzed. First of all, experimental work was done to verify the engine model. Basically, few parameters like pre-tightened force, structure and distribution of bolts have been investigated to figure out how the cylinder bore deformation behaves via finite element analysis. Also, a simple Matlab program was developed to process the data.
2017-03-28
Technical Paper
2017-01-0460
Erina Yasuda, Hiroki Kobayakawa, Seiji Amano, Yuto Otsuki, Tomohiro Ukai
Abstract The number of vehicles with engines using idling stop systems and hybrid systems to improve fuel consumption has recently been increasing. However, with such systems the frequent starts and stops of the engine, where the oil film between the bearings and shaft is squeezed out and direct contact between the components is more likely, can result in increased wear of the engine bearings, particularly in the main bearing. Bearings with resin overlays have been shown to display superior resistance to wear from such start-stop cycles. Moreover, cast iron shafts without quenching treatment have also been used in engines for cost reduction. Because the cast shaft has low hardness and unstable surface graphite after abrasive finishing, increase in the wear amount cannot be suppressed by conventional resin overlay in comparison with steel shaft. Therefore, the resin overlay with improved wear resistance achieved by adding hard particles was developed.
2017-03-28
Journal Article
2017-01-0495
Michael Christian Haverkamp
Abstract The vehicle interior constitutes the multi-sensory environment of driver and passengers. Beside overall design and execution, materials and its surfaces are of specific interest to the customer. They are not only needed to fulfil technical functions, but are in direct focus of the customer’s perception. The perceived quality is based on all sensory data collected by the human perceptual system. Surfaces express design intent and craftsmanship by their visual appearance. Haptic features supervene when materials are touched. And even smell has an influence on the perception of ambience. Although sound is generated nearly every time when fingers slide across a surface, touch-sounds have been disregarded so far. In various cases, these contact sounds are clearly audible. As essential sound responses to haptic activity, they can degrade perceived quality. A method has been developed for a standardized generation of touch-sounds.
2017-03-28
Technical Paper
2017-01-0443
Yong Hyun Nam, Gwansik Yoon
Abstract Significant effort has been expended to improve the sound made by a closing car door. This study focuses on reducing door glass rattle sounds, not only evaluating the rattle influence of door glass support but also introducing an approach to reduce glass rattle noise by using sealing components. The first part of the study is dedicated to minimizing vibration. A jig is constructed to evaluate the influence of a door glass support on the rattling. The jig is employed so that the glass meshing between the A and B pillars can be controlled; the glass holder moves in the x- and z-directions and the belt molding moves in the y-direction. An impact hammer test was adopted for investigating door glass rattle. The frequency response obtained via impact hammer testing is analyzed by varying the glass support points and important factors that should be considered in early design stages are obtained. The second study is about optimizing vibration absorption.
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
2017-01-0457
Kenji Matsumoto, Hideharu Koga
Abstract Piston ring wear in gasoline engine induces deterioration of emissions performance due to leakage of blow-by gas, instability of idling caused by reduced compression in combustion chamber, and to generate early degeneration of engine oil. We examined anti-wear performance of DLC coating on piston ring, which had been recently reported as an effective method for improving the abrasion resistance. As a result, wear rate remained low under the condition of DLC existence on sliding surface, but once DLC was worn out completely, wear of the piston ring was accelerated and its life became shorter than piston ring without DLC. In this research, we designed reciprocating test apparatus that operates at much higher velocity range, and characterized the frictional materials of the piston ring and sleeve and the DLC as a protective film, a vapor phase epitaxy (VPE) was actively used as a means to form certain level of convex and concave shape on its surface.
2017-03-28
Journal Article
2017-01-0500
Yuksel Gur, David Wagner
Abstract With the continuing challenges of future fuel economy targets carbon fiber composite materials are one facet of a lightweighting strategy to enable reduced fuel consumption. In general, use of lightweight materials such as carbon fiber composites in vehicle design generates vehicle NVH performance degradation. To address this potential issue at the design phase, there is a need to develop correlated CAE models for carbon fiber vehicle parts to evaluate the NVH impact of carbon fiber composite material use in vehicle design. To develop correlated CAE models for lightweight vehicle design with the use of carbon fiber composite vehicle body parts, an experimental study was conducted to determine the material and NVH characteristics of the carbon fiber composite materials. In this paper, the damping properties and NVH modal analysis results for structural carbon fiber thermoset composite panels and body parts (B-pillar upper insert and B-pillar lower insert) is presented.
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
2017-01-1304
Alejandro Rosas Vazquez, Fernando Paisano, Diego Santillan Gutierrez
Abstract For many years, the use of in-mold fasteners has been avoided for various reasons including: not fully understanding the load cases in the part, the fear of quality issues occurring, the need for servicing, or the lack of understanding the complexity of all failure modes. The most common solution has been the use of secondary operations to provide attachments, such as, screws, metal clips, heat staking, sonic welding or other methods which are ultimately a waste in the process and an increase in manufacturing costs. The purpose of this paper is to take the reader through the design process followed to design an in-molded attachment clip on plastic parts. The paper explores the design process for in-molded attachment clips beginning with a design concept idea, followed by basic concept testing using a desktop 3D printer, optimizing the design with physical tests and CAE analysis, and finally producing high resolution 3D prototypes for validation and tuning.
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
2017-01-0405
Tianqi Lv, Xingxing Feng, Peijun Xu, Yunqing Zhang
Abstract Three constitutive models which capture the amplitude and frequency dependency of filled elastomers are implemented for the conventional engine mounts of automotive powertrain mounting system (PMS). Firstly, a multibody dynamic model of a light duty truck is proposed, which includes 6 degrees of freedom (DOFs) for the PMS. Secondly, Three constitutive models for filled elastomers are implemented for the engine mounts of the PMS, including: (1) Model 1: Kelvin-Voigt model; (2) Model 2: Fractional derivative Kelvin-Voigt model combined with Berg’s friction; (3) Model 3: Generalized elastic viscoelastic elastoplastic model. The nonlinear behaviors of dynamic stiffness and damping of the mounts are investigated. Thirdly, simulations of engine vibration dynamics are presented and compared with these models and the differences between common Kelvin-Voigt model and other constitutive models are observed and analyzed.
2017-03-28
Journal Article
2017-01-0290
Veera Aditya Yerra, Srikanth Pilla
Abstract The advancements in automation, big data computing and high bandwidth networking has expedited the realization of Industrial Internet of Things (IIoT). IIoT has made inroads into many sectors including automotive, semiconductors, electronics, etc. Particularly, it has created numerous opportunities in the automotive manufacturing sector to realize the new aura of platform concepts such as smart material flow control. This paper provides a thought provoking application of IIoT in automotive composites body shop. By creating a digital twin for every physical part, we no longer need to adhere to the conventional manufacturing processes and layouts, thus opening up new opportunities in terms of equipment and space utilization. The century-old philosophy of the assembly line might not be the best layout for vehicle manufacturing, thus proposing a novel assembly grid layout inspired from a colony of ants working to accomplish a common goal.
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
Journal Article
2017-01-0329
Ayhan Ince
Abstract Driveline and suspension notched components of off-road ground vehicles often experience multiaxial fatigue failures along notch locations. Large nominal load histories may induce local elasto-plastic stress and strain responses at the critical notch locations. Fatigue life prediction of such notched components requires detailed knowledge of local stresses and strains at notch regions. The notched components that are often subject to multiaxial loadings in services, experience complex stress and strain responses. Fatigue life assessment of the components utilizing non-linear Finite Element Analysis (FEA) require unfeasibly inefficient computation times and large data. The lack of more efficient and effective methods of elasto-plastic stress-strain calculation may lead to the overdesign or earlier failures of the components or costly experiments and inefficient non-linear FEA.
2017-03-28
Journal Article
2017-01-0327
Christian Gaier, Stefan Fischmeister, Julia Maier, Gerald Pinter
Abstract Lightweight constructions and the reduction of production time and costs is of increasingly importance. Therefore, engineers make a lot of effort to replace metallic parts by other materials. Carbon fiber reinforced laminates are suitable in many cases because of their high specific strength and the low specific weight. The available material-data of this material group from datasheets are mostly static values like tensile strength and fracture elongation. For the fatigue assessment of parts regarding geometry, loading conditions and material behavior, static material data are not sufficient, but also the knowledge of the local S-N curve is necessary. Component specific effects, such as fiber orientation, type of loading, mean stress, temperature, production process and many more, essentially influence these local S-N curves, determined by the material.
2017-03-28
Journal Article
2017-01-0342
Benjamin Möller, Alessio Tomasella, Rainer Wagener, Tobias Melz
Abstract The cyclic material behavior is investigated, by strain-controlled testing, of 8 mm thick sheet metal specimens and butt joints, manufactured by manual gas metal arc welding (GMAW). The materials used in this investigation are the high-strength structural steels S960QL, S960M and S1100QL. Trilinear strain-life curves and cyclic stress-strain curves have been derived for the base material and the as-welded state of each steel grade. Due to the cyclic softening in combination with a high load level at the initial load cycle, the cyclic stress-strain curve cannot be applied directly for a fatigue assessment of welded structures. Therefore, the transient effects have been analyzed in order to describe the time-variant material behavior in a more detailed manner. This should be the basis for the enhancement of the fatigue life estimation.
2017-03-28
Journal Article
2017-01-0346
Radwan Hazime, Thomas Seifert, Jeremy Kessens, Frank Ju
Abstract A complete thermomechanical fatigue (TMF) life prediction methodology is developed for predicting the TMF life of cast iron cylinder heads for efficient heavy duty internal combustion engines. The methodology uses transient temperature fields as thermal loads for the non-linear structural finite-element analysis (FEA). To obtain reliable stress and strain histories in the FEA for cast iron materials, a time and temperature dependent plasticity model which accounts for viscous effects, non-linear kinematic hardening and tension-compression asymmetry is required. For this purpose a unified elasto-viscoplastic Chaboche model coupled with damage is developed and implemented as a user material model (USERMAT) in the general purpose FEA program ANSYS. In addition, the mechanism-based DTMF model for TMF life prediction developed in Part I of the paper is extended to three-dimensional stress states under transient non-proportional loading conditions.
2017-03-28
Journal Article
2017-01-0344
Christoph Bleicher, Rainer wagener, Heinz Kaufmann, Tobias Melz
Abstract For the design of thick-walled nodular cast iron components, fatigue assessment, especially in the context of local imperfections in the material, is a challenging task. Not only the cyclic material behavior of the sound baseline material, but also the cyclic behavior of materials with imperfections, such as shrinkages, dross and chunky graphite, needs to be considered during the design process of cast iron components. In addition to this, new materials, such as solid solution strengthened alloys, offer new possibilities in lightweight design, but need to be assessed concerning their fatigue strength and elastic-plastic material behavior. If a safe and reproducible fatigue assessment for any component cannot be performed and a secure usage is therefore not given, the cast components are generally rejected, leading to a loss of additional material, energy and money for recasting the component.
2017-03-28
Journal Article
2017-01-0349
Thomas Seifert, Philipp von Hartrott, Kristopher Boss, Paul Wynthein
Abstract Cast iron materials are used as materials for cylinder heads for heavy duty internal combustion engines. These components must withstand severe cyclic mechanical and thermal loads throughout their service life. While high-cycle fatigue (HCF) is dominant for the material in the water jacket region, the combination of thermal transients with mechanical load cycles results in thermomechanical fatigue (TMF) of the material in the fire deck region, even including superimposed TMF and HCF loads. Increasing the efficiency of the engines directly leads to increasing combustion pressure and temperature and, thus, lower safety margins for the currently used cast iron materials or alternatively the need for superior cast iron materials. In this paper (Part I), the TMF properties of the lamellar graphite cast iron GJL250 and the vermicular graphite cast iron GJV450 are characterized in uniaxial tests and a mechanism-based model for TMF life prediction is developed for both materials.
Viewing 241 to 270 of 15996