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Viewing 1 to 30 of 14239
Technical Paper
2014-09-15
Kai Chen
The synthetic paraffinic kerosine (SPK) produced via HEFAs is of great interest for civil aviation industry as it exhibits an excellent thermal oxidative stability with significantly lower particulate matter emission. However, due to its aromatic free characteristics, the widespread use of SPK is limited by its compatibility with non-metal materials such as fuel tank elastomers. In this research the compatibility of SPK and its blends with widely used aircraft fuel tank elastomers were systematically studied. Experimental results demonstrated the volume swellability of all selected materials showed a linear relationship with volume percentage of No.3 jet fuel in SPK blend. The increase of volume percentage of No.3 jet fuel in the SPK blend increased volume swellability for all materials except fluorosilicone gasket. The alkyl benzenes and naphthalenes in the blend acted as the hydrogen donors, which facilitated the formation of polymer matrix and led to the increase of the distance between polymer chains.
Technical Paper
2014-04-20
Ala Qattawi, Mahmoud Abdelhamid, Ahmad Mayyas, Mohammed Omar
1 The manufacturing of Origami based sheet metal products is a promising technology, mostly in terms of reducing the tooling and process complexity. This procedure can also be called fold forming, as it depends on exclusively shaping the required geometry via sequence of bends. However, the design analysis and modeling of folded sheet metal products are not fully mature, especially in terms of determining the best approach for transferring the analysis from a three-dimensional (3D) to a two-dimensional (2D) context. This manuscript discusses the extension of the Origami technique to the fold forming of sheet metal products represented in modeling approach and design considerations for the topological variations, the geometrical validity, and the variance of stress-based performance. This paper also details the optimization metrics that were developed to reflect the design and manufacturing differences among the possible topological and geometrical options for a single part design. These metrics target five different optimization objectives: material utilization, cost, ease of manufacturability, ease of handling, and mechanical behavior estimation.
Technical Paper
2014-04-01
Alessandro Libriani
Abstract Synthetic rubber is used in automobiles for various applications. Tires, seals, gaskets, engine mounts, wiring cables and under the hood hoses are just a few examples. Synthetic rubber is a man-made material that uses several components as polymers, resins, carbon black, fillers, vulcanizing agents, reinforcement agents. It is a material that heavily depends on oil for its constituency, therefore it has a large carbon footprint. This study proposes the use of natural filler for automotive seals using synthetic rubber in order to reduce the impact on the environment. Calcium carbonate is the most preponderant choice as material filler because it is abundant in nature and is mined extensively. Calcium carbonate is also present in several structures in nature. Oyster shells have a great amount of it as well as egg shells. Egg shells also constitute an environmental bio-hazard when discarded in a landfill due to the organic inner membrane. The use of discarded egg shells is limited to few applications, mainly pharmaceutical.
Technical Paper
2014-04-01
Matija Hoic, Nenad Kranjcevic, Zvonko Herold, Josko Deur, Vladimir Ivanovic
Clutch wear is dominantly manifested as the reduction of friction plate thickness. For dry dual clutch with position-controlled electromechanical actuators this affects the accuracy of normal force control because of the increased clutch clearance. In order to compensate for the wear, dry dual clutch is equipped with wear compensation mechanism. The paper presents results of experimental characterization and mathematical modeling of two clutch wear related effects. The first one is the decrease of clutch friction plate thickness (i.e. increase of clutch clearance) which is described using friction material wear rate experimentally characterized using a pin-on-disc type tribometer test rig. The second wear related effect, namely the influence of the clutch wear compensation mechanism activation at various stages of clutch wear on main clutch characteristics, was experimentally characterized using a clutch test rig which incorporates entire clutch with related bell housing. Finally, the previously proposed and experimentally validated physical clutch model, which was focused on the clutch actuator and axial dynamics, is extended to capture both wear related effects as a further step towards a more comprehensive overall clutch dynamics model.
Technical Paper
2014-04-01
Xingyu Liang, Yin Liu, Ge-Qun Shu, Zhengnan Yuhan, Yuesen Wang
Abstract In the present paper, a three-dimensional numerical analysis model based on elastic deformation was applied to analyze the compression top piston ring-liner friction of heavy duty diesel engine, considering the rheological lubrication, the newton fluid model was applied to the numerical analysis. The result illuminates that the turning point of friction transforms from rigid hydrodynamic lubrication to elastohydrodynamic lubrication is around 4°∼8°CRA BTDC (crank angle before top dead center) on the compression stroke in this calculation model. In comparison, the surface elastic deformation was started near 10°CRA BTDC on the compression stroke which is significantly clearer than the lubricant elastic deformation. A friction tester was applied to verify the calculation results. The experiment proved that the model based on elastic deformation is closer to the actual situation and the calculation result at a lower temperature is more precise than that of higher temperature.
Technical Paper
2014-04-01
Michael D. Kass, Mark W. Noakes, Brian Kaul, Dean Edwards, Timothy Theiss, Lonnie Love, Ryan Dehoff, John Thomas
Abstract The performance of a 4cc two-stroke single cylinder glow plug engine was assessed at wide open throttle for speeds ranging from 2000 to 7000RPM. The engine performance was mapped for the stock aluminum head and one composed of titanium, which was printed using additive manufacturing. The engine was mounted to a motoring dynamometer and the maximum torque was determined by adjusting the fuel flow. Maximum torque occurred around 3000 to 3500RPM and tended to be higher when using the aluminum head. At slower speeds, the titanium head produced slightly higher torque. For each test condition, maximum torque occurred at leaner conditions for the titanium head compared to the stock aluminum one. Higher efficiencies were observed with the aluminum head for speeds greater than 3000RPM, but the titanium heads provided better efficiency at the lower speed points. The titanium head was equipped with an in-cylinder pressure sensor and the combustion performance was assessed at maximum torque for speeds of 4000, 6000, and 7000RPM.
Technical Paper
2014-04-01
Mersin Hurpekli, Rifat Yilmaz, Emin Kondakci, Nuri Solak
Abstract Honing is a low-speed abrading process to remove metallic and non-metallic materials from a surface. Honing corrects surface errors produced by other machining operations prior to honing. Moreover,, the honing grooves, the volume and the direction of the valleys control the amount of oil available, by keeping the oil on the bore surface and by improving the spreading of the oil. The traditional honing process that uses ceramic abrasives has been replaced by the superior abrasives that is Metal Bonded Diamond [1,2]. However, the main drawback of diamond honing is that it leaves more torn metal and folded metal on surface [3]. The folded and / or torn metal partially covers the honing grooves and interrupts oil flow in groove. Hence, it causes abrasive wear as axial scratches on the cylinder surface. Diamond is the strongest material known that is less friable, wear very little, requires more pressure and tends to plough through metal surface rather than cut. On the other hand, conventional abrasives that are ceramic abrasives have self-sharpening properties and higher friability.
Technical Paper
2014-04-01
Michael J. Plumley, Victor Wong, Mark Molewyk, Soo-Youl Park
Abstract Lubricant viscosity along the engine cylinder liner varies by an order of magnitude due to local temperature variation and vaporization effects. Tremendous potential exists for fuel economy improvement by optimizing local viscosity variations for specific operating conditions. Methods for analytical estimation of friction and wear in the power-cylinder system are reviewed and used to quantify opportunities for improving mechanical efficiency and fuel economy through lubricant formulation tailored specifically to liner temperature distributions. Temperature dependent variations in kinematic viscosity, density, shear thinning, and lubricant composition are investigated. Models incorporating the modified Reynolds equation were used to estimate friction and wear under the top ring and piston skirt of a typical 11.0 liter diesel engine. Friction losses were analyzed in the liner local position and temperature domains, and practical considerations for obtaining optimal viscosity profiles are reviewed with regard to the limitations of viscosity modifiers.
Technical Paper
2014-04-01
Praveensingh Jadhav, Aditya Nanda, Manas Tripathi, Amit Kumar, Shriganesh Umbarkar
Abstract Global automobile market is very sensitive to vehicle fuel economy. Gross vehicle weight has substantial effects on FE. Hence, for designers it becomes utmost important to work on the weight reduction ideas up to single component level. Fuel delivery pipe (Fuel Rail) is one such component where there is a big potential. Fuel rail is an integral part of the vehicle fuel system and is mounted on the engine. Primarily it serves as a channel of fuel supply from fuel tank through fuel lines to the multiple fuel injectors, which further sprays the fuel into intake ports at high pressure. Due to opening and closing of injectors, pulsations are generated in fuel lines, so fuel rail also acts as a surge tank as well as a pulsation damper. All these factors make the design of a fuel rail very critical and unique for a particular engine. Materials like aluminum, plastic and sheet metal are generally used for fuel rail manufacturing. In this technical paper, design considerations for plastic fuel rail are explained.
Technical Paper
2014-04-01
Danielle Zeng, Cedric Xia, Jeffrey Webb, Li Lu, Yuan Gan, Xianjun Sun, John Lasecki
Abstract Long glass fiber reinforced (LGFR) composites have been widely used in automotive industry to reduce vehicle weight and maintain relatively high mechanical performances. Due to the injection molding process, the distribution of fiber orientations varies at different locations and through the panel thickness, resulting in anisotropic and non-uniform mechanical properties. The current practice of computer modeling of these materials is generally using isotropic properties adjusted by a certain scale factor. The effect of fiber orientation is not carefully considered due to the complexity of fiber orientation distribution in the LGFR parts. The purpose of this paper is to identify key factors affecting vehicle attribute performances where LGFR composites are used; and provide an efficient way for accurate CAE modeling of LGFR composites. In this study, tensile coupons cut from a simple geometric injection molded plaque are tested. The tested material properties are compared to those from CAE predictions to understand how well the CAE predictions capture the material behavior with fiber orientation accounted for.
Technical Paper
2014-04-01
Bharatesh Adappa Danawade, Ravindra Rachappa Malagi
Abstract The combination of wood and steel together gives better properties than individual materials used alone. The advantage associated with this type of hybridization is composite systems are better than that of non-composite system of same size because the system is stiffer. The purpose of utilization of steel with timber members is mainly for stiffness and strength. Steel adds ductility to composite system. The paper presents the experimental results of the work carried out to study the behavior of specimens prepared in solid teakwood, hollow sectioned steel tube and teakwood filled hollow sectioned steel tube under compression. The circular, rectangular and squared sections were used for study. The interfacial bond between wood and steel is obtained by interference fit and by suitable adhesive for wood-steel composite system. Experimental results showed that Hollow sectioned square steel tube and solid sectioned square teakwood specimens showed highest compressive strength and compressive strength of circular cross sections were lowest.
Technical Paper
2014-04-01
Ashok Mache, Anindya Deb, G.S. Venkatesh
Abstract Natural fiber-based composites such as jute-polyester composites have the potential to be more cost-effective and environment-friendly substitutes for glass fiber-reinforced composites which are commonly found in many applications. In an earlier study (Mache and Deb [1]), jute-polyester composite tubes of circular and square cross-sections were shown to perform competitively under axial impact loading conditions when compared to similar components made of bidirectional E-glass fiber mats and thermo-setting polyester resin. For jute-reinforced plastic panels to be feasible solutions for automotive interior trim panels, laminates made of such materials should have adequate perforation resistance. In the current study, a systematic characterization of jute-polyester and glass-polyester composite laminates made by compression molding is at first carried out under quasi-static tensile, compressive and flexural loading conditions. Low velocity impact perforation tests at speeds of around 4 m/s are then performed in an instrumented drop-weight testing device on square plates extracted from the same laminates.
Technical Paper
2014-04-01
Massimiliana Carello, Andrea Giancarlo Airale, Alessandro Ferraris
Abstract The use of composite materials is very important in automotive field to meet the European emission and consumption standards set for 2020. The most important challenge is to apply composite materials in structural applications not only in racing vehicles or supercars, but also in mass-production vehicles. In this paper is presented a real case study, that is the suspension wishbone arm (with convergence tie and pull-rod system) of the XAM 2.0 urban vehicle prototype, that it has the particular characteristics that the front and rear, and left and right suspension system has the same geometry. The starting point has been an existing solution made in aluminum to manufacture a composite one. The first step was the development of a dynamic model of the vehicle to understand the suspension loads and to define the suspension weight and stiffness target with respect to the solution made on aluminum, because it was necessary to understand the tensil strain on the component to simplify and optimize the geometry.
Technical Paper
2014-04-01
Jingsi Wu, Owusu Agyeman Badu, Yonchen Tai, Albert R. George
While many composite monocoque and semi-monocoque chassis have been built there is very little open literature on how to design one. This paper considers a variety of issues related to composite monocoque design of an automotive chassis with particular emphasis on designing a Formula SAE or other race car monocoque chassis. The main deformation modes and loads considered are longitudinal torsion, local bending around mounting points, and vertical bending. The paper first considers the design of elements of an isotropic material monocoque that has satisfactory torsional, hardpoint, and vertical bending stiffness. The isotropic analysis is used to gain insight and acquire knowledge about the behavior of shells and monocoque structures when subjected to a vehicle's applied loads. The isotropic modeling is then used to set initial design targets for a full anisotropic composite analysis. The flexibility in composite layout and core design coupled with the superior material properties of carbon fiber composites is used to design and move toward an optimized monocoque composite design and layup to obtain satisfactory torsional, hardpoint and bending stiffnesses with minimal weight.
Technical Paper
2014-04-01
Songgang Li, Guobiao Yand, Weiming Zeng
Abstract The port structure consisting of spur pile, vertical pile and beam is subjected to impact loads, so its internal stress state of each point will rapidly change over time. Dynamic photoelastic method is used to study the dynamic stress and stress wave propagation. With epoxy resin and other materials, a photoelastic model of beam to column connection structure is processed and product. The dynamic response of the model under the impact load by the free fall is researched by the dynamic photoelastic method, and recorded by the new digital dynamic photoelastic system with a laser source and high-speed photography system. The internal dynamic stress propagation and distribution, the maximum shear stress and the dynamic stress concentration problems can be obtained by analyzing the dynamic response. Researching on the key part under impact load using dynamic photoelastic method can furnish the experimental evidence of transient stress phenomenon for theoretical research and engineering applications.
Technical Paper
2014-04-01
Yi-Hsin Chen, Xu Chen, Nan Xu, Lianxiang Yang
Abstract The residual stresses found in components are mainly due to thermal, mechanical and metallurgical changes of material. The manufacturing processes such as fabrication, assembly, welding, rolling, heat treatment, shot peening etc. generate residual stresses in material. The influence of residual stress can be beneficial or detrimental depending on nature and distribution of the residual stress in material. In general, the compressive residual stress can increase the fatigue life of material because it provides greater resistance for crack initiation and propagation. A significant number of improvements for residual stress measurement techniques have occurred in last few decades. The most popular technique of residual stress measurement is based on the principle of strain gage rosette and hole drilling (ASTM E837-01, destructive). Although this technique is effective for some applications, strain gages provide the localized or averaged data and cannot capture the peak or high resolution data when this technique is applied on high strain gradient areas.
Technical Paper
2014-04-01
Guobiao Yang, Jingyu Wang, Qirong Zhu, Ruhua Fang, Lianxiang Yang
Abstract With the rapid development of computing technology, high-speed photography system and image processing recently, in order to meet growing dynamic mechanical engineering problems demand, a brief description of advances in recent research which solved some key problems of dynamic photo-elastic method will be given, including:(1) New digital dynamic photo-elastic instrument was developed. Multi-spark discharge light source was replaced by laser light source which was a high intensity light source continuous and real-time. Multiple cameras shooting system was replaced by high-speed photography system. The whole system device was controlled by software. The image optimization collection was realized and a strong guarantee was provided for digital image processing. (2)The static and dynamic photo-elastic materials were explored. The new formula and process of the dynamic photo-elastic model materials will be introduced. The silicon rubber mold was used without the release agent. The epoxy resin sheet or block was solidified at room temperature and could be poured accurately once.
Technical Paper
2014-04-01
Yousof Azizi, Vaidyanadan Sundaram, Patricia Davies, Anil Bajaj
Flexible polyurethane foam is the main cushioning element used in car seats. Optimization of an occupied seat's static and dynamic behavior requires models of foam that are accurate over a wide range of excitation and pre-compression conditions. In this research, a method is described to estimate the parameters of a global model of the foam behavior from data gathered in a series of impulse tests at different settling points. The estimated model is capable of describing the responses gathered from all the impulse tests using a unique set of parameters. The global model structure includes a nonlinear elastic term and a hereditary viscoelastic term. The model can be used to predict the settling point for each mass used and, by expanding the model about that settling point, local linear models of the response to impulsive excitation can be derived. From this analysis the relationship between the local linear model parameters and the global model parameters is defined. A series of experiments are conducted using different sized masses on the foam block.
Technical Paper
2014-04-01
Shweta Rawat, Soumya Kanta Das
Abstract With the ever increasing emphasis on vehicle occupant safety, the safety of pedestrians is getting obscured behind the A-pillars that are expanding in order to meet the federal roof crush standards. The serious issue of pillar blind spots poses threats to the pedestrians who easily disappear from driver's field of view. To recognize this blinding danger and design the car around the driver's eye, this paper proposes the implementation of Aluminum Oxynitride marked under name AlON by Surmet Corporation for fabrication of A-pillars that can allow more than 80% visibility through them. AlON is a polycrystalline ceramic with cubic spinel crystal structure and is composed of aluminum, oxygen and nitrogen. With hardness more than 85% than sapphire, its applications range from aerospace to defense purposes which qualify it in terms of strength and thus imply that it can be conveniently used as A-pillars in vehicles. Furthermore, it possesses characteristics of being bonded to metals as well.
Technical Paper
2014-04-01
Benoit Bidaine, Laurent Adam, Roger Assaker, Hanson Chang, Marc Duflot, Bender Kutub, Emmanuel Lacoste
Abstract In the steady quest for lightweighting solutions, continuous carbon fiber composites are becoming more approachable for design, now not only used in the aerospace but also the automotive industries. Carbon Fiber Reinforced Plastics (CFRP) are now being integrated into car body structures, used for their high stiffness and strength and low weight. The material properties of continuous carbon fiber composites are much more complex than metal, especially with respect to failure; this is further complicated by the fact that a single part is typically made from stacks of several unidirectional plies, each with a different fiber orientation. Hence failure occurs because of various mechanisms taking place at the ply level (matrix cracking, fiber breakage, fiber-matrix debonding) or between the plies (delamination). These mechanisms remain not fully understood and are investigated through experimental and virtual testing. To predict composite failure, we have developed advanced simulation strategies combining finite element analysis (FEA) and nonlinear micromechanical material modeling.
Technical Paper
2014-04-01
Weidong Zhang, Mingchao Guo, Paul Stibich, Ram Bhandarkar
Abstract This paper discusses CAE simulation methods to predict the thermal induced buckling issues when vehicle body panels are subjected to the elevated temperature in e-coat oven. Both linear buckling analysis and implicit quasi-static analysis are discussed and studied using a quarter cylinder shell as an example. The linear buckling analysis could produce quick but non-conservative buckling temperature. With considering nonlinearity, implicit quasi-static analysis could predict a relative conservative critical temperature. In addition, the permanent deformations could be obtained to judge if the panel remains visible dent due to the buckling. Finally these two approaches have been compared to thermal bucking behavior of a panel on a vehicle going through thermal cycle of e-coat oven with the excellent agreement on its initial design and issue fix design. In conclusion, the linear buckling analysis could be used for quick thermal buckling evaluation and comparison on a series of proposals.
Technical Paper
2014-04-01
Alessandro Cristofori, Denis Benasciutti
Abstract This paper presents a fatigue criterion based on stress invariants for the frequency-based analysis of multiaxial random stresses. The criterion, named “Projection-by-Projection” (PbP) spectral method, is a frequency-based reformulation of its time-domain definition. In the time domain PbP method, a random stress path is first projected along the axes of a principal reference frame in the deviatoric space, thus defining a set of uniaxial random stress projections. In the frequency-domain approach, the damage of stress projections is estimated from the stress PSD matrix. Fatigue damage of the multiaxial stress is next calculated by summing up the fatigue damage of every stress projection. The criterion is calibrated on fatigue strength properties for axial and torsion loading. The calculated damage is shown to also depend on the relative ratio of hydrostatic to deviatoric stress components. The frequency-based multiaxial analysis of an L-shaped steel beam excited by a random input acceleration is proposed as an illustrative example.
Technical Paper
2014-04-01
Barry (Baizhong) Lin, Mike Gundle, Mike Rowley, Alan Aloe, Frederick Zweng, Eric Blackburn, Chandra Thandhayuthapani, Chandra Thonta, Edward Law, Kah Wah Long, Mike Temkin, Zachary Calkins
Abstract Fuel Tank Straps very often get different durability fatigue test results from different types of durability testing such as shaker table vibration, road test simulator (RTS) vehicle testing and proving ground vehicle durability testing. One test produces good durability results and other may indicate some durability risk. A special study was conducted to address this inconsistency. It was found that fuel level in the tank plays a big role in fuel tank strap durability. Higher fuel levels in a tank produce higher loads in straps and lower fatigue life. This paper will use a CAE fuel tank strap model and acquired proving ground strap load data to study fuel level influence in fuel tank strap durability. The fuel level study includes a full tank of fuel, 3 quarters tank of fuel, a half tank of fuel and one quarter tank of fuel. Based on CAE results of one 32 gallon fuel tank it is observed that fuel tank strap fatigue life improves by one order of magnitude or 10 times for every quarter tank of fuel level reduction.
Technical Paper
2014-04-01
Wenxin Qin, Fred Zweng, Sandip Datta
Abstract In order to take into account the local material non-linear elastic-plastic effects generated by notches, Glinka proposed the equivalent strain energy density (ESED) Criterion which has been widely accepted and used in fatigue theory and calculation for the last few decades. In this paper, Glinka's criterion is applied to structural optimization design for elastic-plastic correction to consider material non-linear elastic-plastic effects. The equivalent (fictitious) stress was derived from Glinka's Criterion equation for the commonly used Ramberg-Osgood and bi-linear stress and strain relationships. This equivalent stress can be used as the stress boundary constraint threshold in structural optimization design to control the elastic-plastic stress or strain in nonlinear optimization. Examples demonstrated this application was an efficient and effective practice within the material non-linear elastic-plastic range when using the equivalent elastic stress as constraints in automotive engineering structural optimization designs.
Technical Paper
2014-04-01
Timothy Palmer, Neil Bishop
Abstract This paper presents a fundamental conceptual change to the traditional CAE based fatigue analysis process. Traditional approaches take the responses from a stress solver and these are then transferred into a secondary fatigue analysis step. In this way fatigue is, and always has been, treated as a post processing step. The new conceptual change described in this paper involves combining the two separate tasks into one (stress and fatigue together). This results in a simple, elegant and more powerful Durability Management concept. This new process requires no large data files to be transferred, no complicated file management and it is likely that whole fatigue calculation process can be done in memory. This makes it possible to perform optimization with fatigue life as the constraint. It also facilitates full body fatigue life calculations, including dynamic behavior, for much larger models than was previously possible. Within this new process, fatigue is treated as part of the solve process and not as a post processing operation.
Technical Paper
2014-04-01
Ali Fatemi, Steve Mellot, Abolhassan Khosrovaneh, Charles Buehler
Abstract An experimental investigation was conducted to evaluate tensile and fatigue behaviors of two thermoplastics, a neat impact polypropylene and a mineral and elastomer reinforced polyolefin. Tensile tests were performed at various strain rates at room, −40°C, and 85°C temperatures with specimens cut parallel and perpendicular to the mold flow direction. Tensile properties were determined from these tests and mathematical relations were developed to represent tensile properties as a function of strain rate and temperature. For fatigue behavior, the effects considered include mold flow direction, mean stress, and temperature. Tension-compression as well as tension-tension load-controlled fatigue tests were performed at room temperature, −40°C and 85°C. The effect of mean stress was modeled using the Walker mean stress model and a simple model with a mean stress sensitivity factor.
Technical Paper
2014-04-01
Virgiliu-Adrian Savu, Yung-Li Lee, Anthony Han, Azadeh Narimissa, Amir Kazemi
Abstract Dang Van (Dang Van et al., 1982 and Dang Van, 1993) states that for an infinite lifetime (near fatigue limit), crack nucleation in slip bands may occur at the most unfavorable oriented grains, which are subject to plastic deformation even if the macroscopic stress is elastic. Since the residual stresses in these plastically deformed grains are induced by the restraining effect of the adjacent grains, it is assumed that the residual stresses are stabilized at a mesoscopic level. These stresses are currently approximated by the macroscopic hydrostatic stress defined by the normal stresses to the faces of an octahedral element oriented with the faces symmetric to the principal axis; mathematically they are equal to each other and they are the average of the principal stresses. This paper proposes and supports the novel hypothesis of normal stress to the maximum shear stress plane being an alternative to the octahedral normal stress, and better aligning with the restraining effect of the adjacent grains defined by Dang Van Multi Scale Approach.
Technical Paper
2014-04-01
Oday Ibraheem Abdullah, Josef Schlattmann
Abstract Most of failures in automotive friction clutches occur due to the excessive heat generated between the contact surfaces during the slipping period; for this reason, the accurate calculation of the heat generation during the slipping is considered an essential item in the successful design process to avoid the failures due to the high thermal stresses. A finite element technique has been used to study the temperature field, the heat generation and the contact pressure distribution when friction disc slides over the steel disc. Analysis has been completed using a three dimensional model to simulate the thermo-structural coupling in automotive clutches. ANSYS software has been used to perform the numerical calculation in this paper.
Technical Paper
2014-04-01
Romeo Sephyrin Fono-Tamo
Abstract The development of a non-asbestos automotive brake pad using palm kernel shell (PKS) as friction filler material is presented. This was with a view to exploiting the characteristics of PKS, which are otherwise largely deposited as waste from palm oil production, to make substitution for asbestos which has been found to be carcinogenic. Two sets of brake pads with identical ingredients but using either PKS or asbestos as base material were produced, following standard procedures employed by a commercial brake pad manufacturer. The physical, thermal, mechanical and the wear characteristics of the PKS-based brake pads were evaluated, compared with the values for the asbestos-based brake pads, and weighted against established recommendations for friction materials for road vehicle brake pads. The PKS based brake pad was characterized by 32.34 Brinell hardness number; 0.62%, swell and growth; 3375 N/s, bonding to back plate, and phase change at 689.5°C. The coefficient of friction of the experimental brake pad on cast iron was 0.43; whilst, wear rate was 9.17 E-5 g/min and exhibiting a third order polynomial with run-in time.
Technical Paper
2014-04-01
Paul R. Stibich, Yu Hsien Wu, Weidong Zhang, Michao Guo, Kumar Srinivasan, Sreekanth Surapaneni
Abstract This paper describes a comprehensive methodology for the simulation of vehicle body panel buckling in an electrophoretic coat (electro-coat or e-coat) and/or paint oven environment. The simulation couples computational heat transfer analysis and structural analysis. Heat transfer analysis is used to predict temperature distribution throughout a vehicle body in curing ovens. The vehicle body temperature profile from the heat transfer analysis is applied as an input for a structural analysis to predict buckling. This study is focused on the radiant section of the curing ovens. The radiant section of the oven has the largest temperature gradients within the body structure. This methodology couples a fully transient thermal analysis to simulate the structure through the electro-coat and paint curing environments with a structural, buckling analysis. The ability to predict the buckling phenomenon using a virtual simulation will reduce the risk of late production changes to the vehicle class “A” surfaces.
Viewing 1 to 30 of 14239