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Viewing 151 to 180 of 15992
2017-03-28
Technical Paper
2017-01-1666
David Weiss, Orlando Rios
Abstract Aluminum alloys containing cerium have excellent castability and retain a substantial fraction of their room temperature strength at temperatures of 200°C and above. High temperature strength is maintained through a thermodynamically trapped, high surface energy intermetallic. Dynamic load partitioning between the aluminum and the intermetallic increases mechanical response. Complex castings have been produced in both permanent mold and sand castings. This versatile alloy system, using an abundant and inexpensive co-product of rare earth mining, is suitable for parts that need to maintain good properties when exposed to temperatures between 200 and 315°C.
2017-03-28
Technical Paper
2017-01-1665
Qigui Wang, Peggy Jones, Yucong Wang, Dale Gerard
Abstract With the increasing use of aluminum shape castings in structural applications in automobiles, assurance of cast product integrity and performance has become critical in both design and manufacturing. In this paper, the latest understanding of the relationship between casting quality and mechanical properties of aluminum castings is summarized. Examples of newly developed technologies for alloy design, melting and melt treatment, casting and heat treatment processes in aluminum casting are reviewed. Robust design and development of high integrity aluminum castings through an Integrated Computational Materials Engineering (ICME) approach is also discussed.
2017-03-28
Technical Paper
2017-01-1663
Alan Druschitz, Christopher Williams, Erin Connelly, Bob Wood
Abstract Binder jetting of sand molds and cores for metal casting provides a scalable and efficient means of producing metal components with complex geometric features made possible only by Additive Manufacturing. Topology optimization software that can mathematically determine the optimum placement of material for a given set of design requirements has been available for quite some time. However, the optimized designs are often not manufacturable using standard metal casting processes due to undercuts, backdraft and other issues. With the advent of binder-based 3D printing technology, sand molds and cores can be produced to make these optimized designs as metal castings.
2017-03-28
Technical Paper
2017-01-1626
Tomas Poloni, Jianbo Lu
Abstract This paper proposes a method to make diagnostic/prognostic judgment about the health of a tire, in term of its wear, using existing on-board sensor signals. The approach focuses on using an estimate of the effective rolling radius (ERR) for individual tires as one of the main diagnostic/prognostic means and it determines if a tire has significant wear and how long it can be safely driven before tire rotation or tire replacement are required. The ERR is determined from the combination of wheel speed sensor (WSS), Global Positioning sensor (GPS), the other motion sensor signals, together with the radius kinematic model of a rolling tire. The ERR estimation fits the relevant signals to a linear model and utilizes the relationship revealed in the magic formula tire model. The ERR can then be related to multiple sources of uncertainties such as the tire inflation pressure, tire loading changes, and tire wear.
2017-03-28
Technical Paper
2017-01-1633
Eiji Kojima, Kazuhiko Kano, Hiroyuki Wado, Noriyuki Iwamori
Abstract In automotive applications, magnetic field sensors are widely used for detecting position and current. However, magnetic field sensors are required to be highly precise with good usability. To satisfy demand, we have developed a graphene Hall sensor that senses magnetic fields by the Hall effect. The sensitivity of a Hall sensor is proportional to the carrier mobility, and graphene has an extremely high carrier mobility compared with conventional materials like Si, GaAs and InSb. Thus, graphene Hall sensors are expected to give high sensitivity that will enable sensing of the Earth’s magnetic field. In addition, graphene has a low temperature dependence on carrier mobility due to its ballistic transport, so good usability in actual use is also anticipated. In this paper, we demonstrate a graphene Hall sensor made using conventional Si process technology.
2017-03-28
Technical Paper
2017-01-1461
Sanketh Gowda, Anindya Deb, Goutham Kurnool, Clifford Chou
Abstract Adhesively bonded steel hat section components have been experimentally studied in the past as a potential alternative to traditional hat section components with spot-welded flanges. One of the concerns with such components has been their performance under axial impact loading as adhesive is far more brittle as compared to a spot weld. However, recent drop-weight impact tests have shown that the energy absorption capabilities of adhesively bonded steel hat sections are competitive with respect to geometrically similar spot-welded specimens. Although flange separation may take place in the case of a specimen employing a rubber toughened epoxy adhesive, the failure would have taken place post progressive buckling and absorption of impact energy.
2017-03-28
Technical Paper
2017-01-1443
Lu ZiLin, Gangfeng Tan, Yuxin Pang, YU TANG, Keyu Qian
Abstract The development of the vehicle quantity and the transportation system accompanies the rise of traffic accidents. Statistics shows that nearly 35-45% traffic accidents are due to drivers’ fatigue. If the driver’s fatigue status could be judged in advance and reminded accurately, the driving safety could be further improved. In this research, the blink frequency and eyes movement information are monitored and the statistical method was used to assess the status of the driving fatigue. The main tasks include locating the edge of the human eyes, obtaining the distance between the upper and lower eyelids for calculating the frequency of the driver's blink. The velocity and position of eyes movement are calculated by detecting the pupils’ movement. The normal eyes movement model is established and the corresponding database is updated constantly by monitoring the driver blink frequency and eyes movement during a certain period of time.
2017-03-28
Technical Paper
2017-01-1503
Jared Johan Engelbrecht, Tony Russell Martin, Piyush M. Gulve, Nagarjun Chandrashekar, Amol Dwivedi, Peter Thomas Tkacik, Zachary Merrill
Abstract Most commercial heavy-duty truck trailers are equipped with either a two sensor, one modulator (2S1M) or four sensors, two modulator (4S2M) anti-lock braking system (ABS). Previous research has been performed comparing the performance of different ABS modules, in areas such as longitudinal and lateral stability, and stopping distance. This study focuses on relating ABS module type and wheel speed sensor placement to trailer wheel lock-up and subsequent impact to tire wear for tandem axle trailers with the Hendrickson air-ride suspension. Prior to tire wear inspection, functionality of the ABS system was testing using an ABS scan tool communicating with the SAE J1587 plug access port on the trailer. Observations were documented on trailers using the 2S1M system with the wheel speed sensor placed on either the front or rear axle of a tandem pair.
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
2017-01-1272
Nick Parson, Jerome Fourmann, Jean-Francois Beland
Abstract One of the main applications for aluminum extrusions in the automotive sector is crash structures including crash rails, crash cans, bumpers and structural body components. The objective is usually to optimize the energy absorption capability for a given structure weight. The ability to extrude thin wall multi-void extrusions contributes to this goal. However, the alloy used also plays a significant role in terms of the ability to produce the required geometry, strength - which to a large extent controls the energy absorption capability and the “ductility” or fracture behavior which controls the strain that can be applied locally during crush deformation before cracking. This paper describes results of a test program to examine the crush behavior of a range of alloys typically supplied for automotive applications as a function of processing parameters including artificial ageing and quench rate.
2017-03-28
Technical Paper
2017-01-1265
Nia R. Harrison, S. George Luckey, Breana Cappuccilli, Ghassan Kridli
Abstract The typical paint bake cycle includes multiple ramps and dwells of temperature through e-coat, paint, and clear coat with exposure equivalent to approximately 190°C for up to 60 minutes. 7xxx-series aluminum alloys are heat treatable, additional thermal exposure such as a paint bake cycle could alter the material properties. Therefore, this study investigates the response of three 7xxx-series aluminum alloys with respect to conductivity, hardness, and yield strength when exposed to three oven curing cycles of a typical automotive paint operation. The results have indicated that alloy composition and artificial aging practice influence the material response to the various paint bake cycles.
2017-03-28
Technical Paper
2017-01-1301
Deepak A. Patil, Hrishikesh Buddhe
Abstract Frontal collisions account for majority of car accidents. Various measures have been taken by the automotive OEMs’ with regards to passive safety. Honeycomb meso-structural inserts in the front bumper have been suggested to enhance the energy absorption of the front structure which is favorable for passive safety. This paper presents the changes in energy absorption capacity of hexagonal honeycomb structures with varying cellular geometries; under frontal impact simulations. Honeycomb cellular metamaterial structure offers many distinct advantages over homogenous materials since their effective material properties depend on both, their constituent material properties and their cell geometric configurations. The effective static mechanical properties such as; the modulus of elasticity, modulus of rigidity and Poisson’s ratio of the honeycomb cellular meso-structures are controlled by variations in their cellular geometry.
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
2017-01-1303
Nobuhisa Yasuda, Shinichi Nishizawa, Maiko Ikeda, Tadashi Sakai
Abstract The purpose of this study is to validate a reverse engineering based design method for automotive trunk lid torsion bars (TLTB) in order to determine a free, or unloaded, shape that meets a target closed shape as well as a specified torque. A TLTB is a trunk lid component that uses torsional restoring force to facilitate the lifting open of a trunk lid, as well as to maintain the open position. Bend points and torque of a TLTB at a closed trunk position are specified by a car maker. Conventionally, a TLTB supplier determines bend points of the free shape by rotating the given bend points from a closed position around a certain axis to satisfy the specified torque at the closed position. Bend points of a deformed TLTB shape in the closed position often do not match the target bend points given by a car maker when designed by the conventional method, which can potentially cause interference issues with surrounding components.
2017-03-28
Technical Paper
2017-01-1298
Kamlesh Yadav, Abhishek Sinha, Rajdeep Singh Khurana
Abstract Vehicle Hood being the face of a passenger car poses the challenge to meet the regulatory and aesthetic requirements. Urge to make a saleable product makes aesthetics a primary condition. This eventually makes the role of structure optimization much more important. Pedestrian protection- a recent development in the Indian automotive industry, known for dynamics of cost competitive cars, has posed the challenge to make passenger cars meeting the regulation at minimal cost. The paper demonstrates structure optimization of hood and design of peripheral parts for meeting pedestrian protection performance keeping the focus on low cost of ownership. The paper discusses development of an in-house methodology for meeting Headform compliance of a flagship model of Maruti Suzuki India Ltd., providing detailed analysis of the procedure followed from introduction stage of regulatory requirement in the project to final validation of the engineering intent.
2017-03-28
Technical Paper
2017-01-0465
HaiYan Yu, Siji Chen
Abstract Carbon Fiber Reinforced Plastic (CFRP) tube is an important material for the lightweight design of automotive structures. Simulation method of CFRP thin-walled tubes subjected to axial compression using MAT54 in LS-DYNA was investigated. Based on the two-layer shell model combined with MAT54, failure strategy and the parameters sensitivity of the model were discussed in detail. Then the simulation model was verified by using duplicate specimens comprised of carbon fiber/epoxy unidirectional prepreg tape. Furthermore, the modeling methods of crush trigger and different types of loading speed were analyzed. In addition, based on the method of equal energy absorption, energy absorption performance of thin-walled circular and square tubes made from four materials including mild steel, high strength steel, aluminum alloy and CFRP were also compared.
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
2017-01-0455
Harshad Hatekar, Baskar Anthonysamy, V. Saishanker, Lakshmi Pavuluri, Gurdeep Singh Pahwa
Abstract Structural elastomer components like bushes, engine mounts are required to meet stringent and contrasting requirements of being soft for better NVH and also be durable at different loading conditions and different road conditions. Silent block bushes are such components where the loading in radial direction of bushes are high to ensure the durability of bushes at high loads, but has to be soft on torsion to ensure good NVH. These requirements present with unique challenge to optimize the leaf spring bush design, stiffness and material characteristics of the rubber. Traditionally, bushes with varying degree of stiffness are selected, manufactured and tested on vehicle and the best one is chosen depending on the requirements. However, this approach is costly, time consuming and iterative. In this study, the stiffness targets required for the bush were analysed using static and dynamic load cases using virtual simulation (MSC.ADAMS).
2017-03-28
Technical Paper
2017-01-0453
Zane Yang
Considered in this study by the use of finite element model is a unit of assembled stator and one-way clutch (OWC) housed in a test setup, where the inner chamber is maintained at a given elevated temperature while its exterior housing surfaces are exposed to the room temperature. The two key components of dissimilar metals are assembled through the conventional interference fitting at their interface surfaces to form a friction joint at the room temperature. Due to the difference in the thermal expansion coefficients of two dissimilar materials, the outer component of aluminum from this joint tends to expand more than the inner component of steel when the temperature rises, thus leading to a possible relaxation in joining connection at their interface.
2017-03-28
Technical Paper
2017-01-1119
Fangwu Ma, Ying Zhao, Yongfeng Pu, Jiawei Wang
Abstract Gear transmission is widely used in mechanical transmission system and acts an important role in automotive industry. Manufacturing errors, assembly looseness, gear wear issues may result in gear backlash, noise and fatigue damage seriously affecting efficiency and service life of gear transmission. For gear transmission assembled, it is important to monitor the conditions of gear meshing and prevent the occurrence of dangerous situations. How to define the issues of gear tooth wear, misaligned bearing, gear eccentricity, backlash, and how to find faulty planetary gear sets and specific issues existing in gear transmission are meaningful and significant to ensure the quality of product. This paper starts from the analysis on gearing mechanism. Based on the behaviors represented by the issues, gear tooth wear, misaligned bearing, gear eccentricity and backlash are demonstrated and explained in detail.
2017-03-28
Technical Paper
2017-01-0505
Aditi Chavannavar
Abstract Polyurethane dispersions (PUDs) have seen rapid growth in recent years as alternatives to their solvent-based analogs. They offer the advantages of enabling low VOC formulations while providing superior appearance and mechanical properties. Polyurethane-acrylic hybrids combine the advantages of a polyurethane dispersion with the benefits of an acrylic emulsion. This synergistic combination offers properties such as good hardness development and chemical resistance in addition to enhanced mechanical properties. In this paper, we discuss new PUD-acrylic hybrids that are NMP and solvent-free, have a pendulum hardness of 100 oscillations compared to a standard acrylic emulsion that has 80; and offer excellent scratch and chemical resistance equivalent to that of an acrylic system. In addition to these, the new polyurethane dispersions provide good haptic qualities and have excellent adhesion to plastic substrates such as ABS, PC and PVC.
2017-03-28
Technical Paper
2017-01-1300
Raj Jayachandran, Bhimaraddi Alavandi, Matt Niesluchowski, Erika Low, Yafang Miao, Yi Zhang
Abstract An engine cooling system in an automotive vehicle comprises of heat exchangers such as a radiator, charge air cooler and oil coolers along with engine cooling fan. Typical automotive engine-cooling fan assembly includes an electric motor mounted on a shroud that encloses the radiator core. One of main drivers of fan shroud design is Noise, Vibration, and Harshness (NVH) requirements without compromising the main function of airflow for cooling requirements. In addition, there is also a minimum stiffness requirement of fan shroud which is often overlooked in arriving at optimal design of it. Low Speed Damageability (LSD) assessment of an automotive vehicle is about minimizing the cost of repair of vehicle damages in low speed crashes. In low speed accidents, these fan motors are subjected to sudden decelerations which cause fan motors to swing forward thereby damaging the radiator core. So designing fan shroud for low speed damageability is of importance today.
2017-03-28
Journal Article
2017-01-1306
Michael Ulizio, DeWitt Lampman, Mukesh Rustagi, Jason Skeen, Chester Walawender
Abstract Automotive manufacturers are requiring lightweight materials, including glazing materials to improve vehicle fuel economy mandates. Since windshields are one of the largest glazing surface areas, reducing the thickness of the glass in its construction can significantly provide weight savings opportunities. Automotive glazing design considerations must include overall glass strength, rigidity, acoustical, and solar performance, which are affected by changes of glass thicknesses. This paper will evaluate those design considerations in the lightweighting of windshield glazings. One important design consideration for the windshield position is the impact of debris from the environment. Lightweighting of glazings in this body position affects the way the construction reacts to an impact. Use of asymmetry in glass plies in a laminated construction can have a marked effect on the part’s impact performance and surface damage creation.
2017-03-28
Journal Article
2017-01-0223
Haolong Liu, Weidong Wen, Xuming Su, Carlos Engler-Pinto, HongTae Kang
Abstract Morphological features of voids were characterized for T300/924 12-ply and 16-ply composite laminates at different porosity levels through the implementation of a digital microscopy (DM) image analysis technique. The composite laminates were fabricated through compression molding. Compression pressures of 0.1MPa, 0.3MPa, and 0.5MPa were selected to obtain composite plaques at different porosity levels. Tension-tension fatigue tests at load ratio R=0.1 for composite laminates at different void levels were conducted, and the dynamic stiffness degradation during the tests was monitored. Fatigue mechanisms were then discussed based on scanning electron microscope (SEM) images of the fatigue fracture surfaces. The test results showed that the presence of voids in the matrix has detrimental effects on the fatigue resistance of the material, depending on the applied load level.
2017-03-28
Journal Article
2017-01-0225
Gabriela Guerra, Ulises Figueroa-López, Andrea Guevara-Morales
Abstract The rapid growth of the emerging markets has pushed the automotive original equipment manufacturers to relocalize production to reduce manufacturing and logistic costs. To ensure an efficient and flexible supply chain, local suppliers are appointed. However, the characteristics of materials available in each region may have minor differences, and when geometry and process design recommendations that were developed for certain materials are implemented for materials under a different regional standard, different results are obtained. Such is the case of the clutch disc spacer bolt, in which its compression during riveting has a direct effect in the noise and vibration isolation of the vehicle.
2017-03-28
Journal Article
2017-01-0230
Louise A. Powell, William E. Luecke, Matthias Merzkirch, Katherine Avery, Tim Foecke
Abstract The introduction of carbon fiber reinforced polymer (CFRP) composites to structural components in lightweight automotive structures necessitates an assessment to evaluate that their crashworthiness dynamic response provides similar or higher levels of safety compared to conventional metallic structures. In order to develop, integrate and implement predictive computational models for CFRP composites that link the materials design, molding process and final performance requirements to enable optimal design and manufacturing vehicle systems for this study, the dynamic mechanical response of unidirectional (UD) and 2x2 twill weave CRFP composites was characterized at deformation rates applicable to crashworthiness performance. Non-standardized specimen geometries were tested on a standard uniaxial frame and an intermediate-to-high speed dynamic testing frame, equipped with high speed cameras for 3D digital image correlation (DIC).
2017-03-28
Journal Article
2017-01-0451
Klaus-Peter Heinig, David A. Stephenson, Timothy G. Beyer
Abstract Thermally sprayed coatings have used in place of iron bore liners in recent aluminum engine blocks. The coatings are steel-based, and are sprayed on the bore wall in the liquid phase. The thermal response of the block structure determines how rapidly coatings can be applied and thus the investment and floor space required for the operation. It is critical not to overheat the block to prevent dimensional errors, metallurgical damage, and thermal stress cracks. This paper describes an innovative finite element procedure for estimating both the substrate temperature and residual stresses in the coating for the thermal spray process. Thin layers of metal at a specified temperature, corresponding to the layers deposited in successive thermal spray torch passes, are applied to the substrate model, generating a heat flux into the block. The thickness, temperature, and application speed of the layers can be varied to simulate different coating cycles.
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
2017-01-0470
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
2017-01-0495
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.
Viewing 151 to 180 of 15992