Criteria

Text:
Display:

Results

Viewing 1 to 30 of 2994
2017-06-05
Technical Paper
2017-01-1856
Junji Yoshida, Koki Tanaka, Rie Nakamoto, Ken Fukasawa
Abstract In this study, we combined operational transfer path analysis (OTPA) method with CAE technique to obtain high contributing vibration modes. A rear frame model of a small construction machine was employed for the analysis. 20 vibration modes were obtained by CAE (eigenmode analysis) under 200 Hz. Subsequently, operational test, in which a sinusoidal input force was given, was carried out. For applying OTPA, acceleration signals at 15 points on the rear frame were used as the reference signals and the cab vibration positioned on the frame via rubber bushes was used as the response signal. These acceleration signals were then measured simultaneously in the operational condition. As the result of OTPA, high contributing principal component modes were calculated and high contributing vibration modes were also extracted using mode shape correlation between them. Two in the 20 calculated vibration modes remained as the important modes to the cab vibration through the analyses.
2017-06-05
Technical Paper
2017-01-1880
Guojian Zhou, Xiujie Tian, Keda Zhu, Wei Huang, Richard E. Wentzel, Melvyn J. Care, Kaixuan Mao, Jiu Hui Wu
Abstract A flexible rebound-type acoustic metamaterial with high sound transmission loss (STL) at low frequency is proposed, which is composed of a flexible, light-weight membrane material and a sheet material - Ethylene Vinyl Acetate Copolymer (EVA) with uneven distributed circular holes. STL was analyzed by using both computer aided engineering (CAE) calculations and experimental verifications, which depict good results in the consistency between each other. An obvious sound insulation peak exists in the low frequency band, and the STL peak mechanism is the rebound-effect of the membrane surface, which is proved through finite element analysis (FEA) under single frequency excitation. Then the variation of the STL peak is studied by changing the structure parameters and material parameters of the metamaterial, providing a method to design the metamaterial with high sound insulation in a specified frequency range.
2017-04-11
Journal Article
2017-01-9625
Souhir Tounsi
Abstract In this paper, we present a design and control methodology of an innovated structure of switching synchronous motor. This control strategy is based on the pulse width modulation technique imposing currents sum of a continuous value and a value having a shape varying in phase opposition with respect to the variation of the inductances. This control technology can greatly reduce vibration of the entire system due to the strong fluctuation of the torque developed by the engine, generally characterizing switching synchronous motors. A systemic design and modelling program is developed. This program is validated following the implementation and the simulation of the control model in the simulation environment Matlab-Simulink. Simulation results are with good scientific level and encourage subsequently the industrialization of the global system.
2017-03-28
Journal Article
2017-01-1569
Amro Elhefnawy, Alhossein sharaf, Hossam Ragheb, Shawky Hegazy
Abstract This paper presents an advanced control system, which integrates three fuzzy logic controllers namely; Direct Yaw-moment Control (DYC), Active Roll-moment Control (ARC) and Active Front Steering (AFS) to enhance vehicle cornering and overturning stability. Based on a well-developed and validated fourteen degree of freedom (DOF) full vehicle model with non-linear tire characteristics, a reference 3-DOF yaw-roll plane vehicle model is introduced to control yaw rate, sideslip angle, and roll angle of the vehicle body. The control actions of both direct yaw and active roll moments are performed by generating differential braking moments across the front wheels, while the control action of the active steering is performed by modifying the steering wheel angle. Different standard cornering tests are conducted in MATLAB / Simulink environment such as J-turn, fishhook and lane change maneuvers.
2017-03-28
Technical Paper
2017-01-1555
Mirosław Jan Gidlewski, Krystof JANKOWSKI, Andrzej MUSZYŃSKI, Dariusz ŻARDECKI
Abstract Lane change automation appears to be a fundamental problem of vehicle automated control, especially when the vehicle is driven at high speed. Selected relevant parts of the recent research project are reported in this paper, including literature review, the developed models and control systems, as well as crucial simulation results. In the project, two original models describing the dynamics of the controlled motion of the vehicle were used, verified during the road tests and in the laboratory environment. The first model - fully developed (multi-body, 3D, nonlinear) - was used in simulations as a virtual plant to be controlled. The second model - a simplified reference model of the lateral dynamics of the vehicle (single-body, 2D, linearized) - formed the basis for theoretical analysis, including the synthesis of the algorithm for automatic control. That algorithm was based on the optimal control theory.
2017-03-28
Technical Paper
2017-01-1560
Wei Liu, Lu Xiong, Bo Leng, Haolan Meng, Renxie Zhang
Abstract In this paper, a novel method is proposed to establish the vehicle yaw stability criterion based on the sideslip angle-yaw rate (β-r) phase plane method. First, nonlinear two degrees of freedom vehicle analysis model is established by adopting the Magic Formula of nonlinear tire model. Then, according to the model in the Matlab/Simulink environment, the β-r phase plane is gained. Emphatically, the effects of different driving conditions (front wheels steering angle, road adhesion coefficient and speed) on the stability boundaries of the phase plane are analyzed. Through a large number of simulation analysis, results show that there are two types of phase plane: curve stability region and diamond stability region, and the judgment method of the vehicle stability domain type under different driving conditions is solved.
2017-03-28
Technical Paper
2017-01-1332
Xin Yang, Zhenfei Zhan, Nanliang Jiang, Junqi Yang, Jun Lu
Abstract To obtain higher efficiency in analysis process, simplification methods for computer-aided engineering (CAE) models are required in engineering. Current model simplification methods can meet certain precision and efficiency requirement, but these methods mainly concentrate on model features while ignoring model mesh which is also critical to efficiency of the analysis process and preciseness of the results. To address such issues, an integrated mesh simplification and evaluation process is proposed in this paper. The mesh is simplified to fewer features (e.g. faces, edges, and vertices) through edge collapsing based on quadric error metric. Then curvatures and normal vectors which are the objects to be evaluated are extracted from the original and simplified models for comparison. To obtain accurate results, the geometric information of mesh nodes and elements are both considered in this evaluation process. The proposed method is implemented on a vehicle crash test.
2017-03-28
Technical Paper
2017-01-0328
Yunkai Gao, Genhai Wang, Jingpeng Han
Abstract The multi-body dynamics simulation and physical iteration were carried out based on the 4-channel road simulation bench, the solution of fatigue test bench which was suitable for cab with frame and suspension was designed. Large load and displacement above the suspension can be loaded on the test bench, and the same weak position of cab exposed on the road test can be assessed well on the fatigue test bench. The effectiveness of the bench test solution was verified though comparative study. And it has important reference for the same type of cab assembly with suspension in the fatigue bench test. According to the durability specifications of cab assembly, a multi-body dynamics model with a satisfactory accuracy was built. And the fixture check and virtual iteration analysis were used to verify the effectiveness of the solution. According to the road load signal analysis and multi-body dynamics analysis results, the test bench with linear guide and spherical joint was built.
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
2017-01-0329
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
Technical Paper
2017-01-0330
Rainer Wagener, Tobias Melz
Abstract Fatigue testing is known to be time consuming and expensive. Therefore, it should be the main target of fatigue research to accelerate the derivation of fatigue properties. Depending on the required properties, strain- or load-controlled fatigue tests have to be performed. Carrying out load-controlled fatigue tests is necessary to derive the influence of mean stresses and notches on the fatigue strength and fatigue life of different materials and joining technologies. In the case of material samples, increasing test frequencies could be a proper way to accelerate the fatigue testing, as long as the increased test frequencies have no influence on the resulting fatigue life. In the case of strain-controlled fatigue tests, it is not possible to increase the test frequencies in order to accelerate the fatigue tests. Therefore, the Incremental Step Test, which allows the derivation of the cyclic stress-strain curve with only one test, was introduced.
2017-03-28
Technical Paper
2017-01-0340
Li Lu, Jane Zhou, Ram Iyer, Jeffrey Webb, Derren Woods, Thomas Pietila
Abstract Injection molding tools are expensive and the fatigue failure during production would result in very costly rework on the tool and downtime. Currently, mold designs are mostly based on expert experience without a careful stress analysis and the mold tool life cycle relies largely on rough estimates. The industry state of the art applies averaged temperature change and peak pressure load on the mold tool. The static analysis is then performed. Mold temperature history and thermal shock are not considered in the durability analysis. In this paper, a transient thermal analysis of the tool is performed in conjunction with the injection molding process simulation. The spatial and temporal variation of temperature, pressure and clamping forces are exported from Moldflow simulation. These histories of temperature and pressure are converted to appropriate loading curves and mapped into Abaqus FEA model.
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
2017-01-0334
Yuexing Duan, Wei Huang, Yunkai Gao, Jingpeng Han
Abstract The frame of a low-speed electric vehicle was treated as the research object in the paper. The fatigue load of the frame was analyzed with multi-body dynamics method and the fatigue life of frame was analyzed with the nominal stress method. Firstly, the multi-body dynamics model of the vehicle was established and the multi-body dynamics simulation was carried out to simulate the condition where the vehicle used to travel. The fatigue load history of the frame was obtained from the simulation. Secondly, the amplitude-frequency characteristic of the fatigue load was analyzed. The frequency of the fatigue load mainly focused on 0~20HZ from the analysis. Thirdly, the modal of frame was analyzed. As the frequency of the fatigue load was less than the natural frequency of the frame, the quasi-static method was selected to calculate the stress history of the frame. Next, the fatigue life of the frame was analyzed based on S-N curve.
2017-03-28
Technical Paper
2017-01-0345
SungChul Cha, Seung-Hyun Hong, Shahriar Sharifimehr
Abstract Fatigue behavior of two types of automotive steel, quenched and tempered SUJ2 and carburized SCM820PRH, which are applied as powertrain parts are studied. These two types of steel are different in their hardness distribution from surface to core. The hardness of quenched and tempered SUJ2 is homogenous, in contrast to that of carburized SCM820PRH (SCM) which decreases from surface to core. These steels are investigated in terms of their monotonic tensile properties and fatigue behavior. A number of predictive methods were used to describe the fatigue behavior of these steels. A simple predictive method is based on approximation of S-N curve from ultimate tensile strength. The well-known Murakami’s defect area method was also applied for the prediction of the high cycle fatigue strength.
2017-03-28
Technical Paper
2017-01-0341
Seyyedvahid Mortazavian, Javid Moraveji, Reda Adimi, Xingfu Chen
Abstract In this study, a finite element analysis method is developed for simulating a camshaft cap punching bench test. Stiffness results of simulated camshaft cap component are correlated with test data and used to validate the model accuracy in terms of material and boundary conditions. Next, the method is used for verification of cap design and durability performance improvement. In order to improve the computational efficiency of the finite element analysis, the punch is replaced by equivalent trigonometric distributed loads. The sensitivity of the finite element predicted strains for different trigonometric pressure distribution functions is also investigated and compared to strain gage measured values. A number of equivalent stress criteria are also used for fatigue safety factor calculations.
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
Technical Paper
2017-01-0343
Xiao Wu, Zhigang Wei, HongTae Kang, Abolhassan Khosrovaneh
Abstract Over the decades, several attempts have been made to develop new fatigue analysis methods for welded joints since most of the incidents in automotive structures are joints related. Therefore, a reliable and effective fatigue damage parameter is needed to properly predict the failure location and fatigue life of these welded structures to reduce the hardware testing, time, and the associated cost. The nodal force-based structural stress approach is becoming widely used in fatigue life assessment of welded structures. In this paper, a new nodal force-based structural stress recovery procedure is proposed that uses the least squares method to linearly smooth the stresses in elements along the weld line. Weight function is introduced to give flexibility in choosing different weighting schemes between elements. Two typical weighting schemes are discussed and compared.
2017-03-28
Technical Paper
2017-01-0355
Edinilson Alves Costa, Neil Bishop, Valdir Cardoso
Abstract In most aspects of mechanical design related to a motor vehicle there are two ways to treat dynamic fatigue problems. These are the time domain and the frequency domain approaches. Time domain approaches are the most common and most widely used especially in the automotive industries and accordingly it is the method of choice for the fatigue calculation of welded structures. In previous papers the frequency approach has been successful applied showing a good correlation with the life and damage estimated using a time based approach; in this paper the same comparative process has been applied but now extended specifically to welded structures. Both the frequency domain approach and time domain approach are used for numerically predicting the fatigue life of the seam welds of a thin sheet powertrain installation bracketry of a commercial truck submitted to variable amplitude loading. Predicted results are then compared with bench tests results, and their accuracy are rated.
2017-03-28
Technical Paper
2017-01-0354
Zhigang Wei, Ranjith Nayaki, Raghuram Mandapati, Jason Hamilton
A probabilistic distribution function roughly consists of two parts: the middle part and the tails. The fatigue life distribution at a stress/load level is often described with two-parameter lognormal or Weibull distribution functions, which are more suitable for modeling the mean (middle) behaviors. The domains of the conventional probabilistic distribution functions are often unbounded, either infinite small (0 for the two-parameter Weibull) or infinite large or both. For most materials in low- and medium-cycle fatigue regimes, the domains of fatigue lives are usually bounded, and the inclusion of the bounds in a probabilistic model is often critical in some applications, such as product validation and life management. In this paper, four- and five-parameter Weibull distribution functions for the probabilistic distributions with bounds are developed. Finally, the applications of these new models in fatigue data analysis and damage assessment are provided and discussed.
2017-03-28
Technical Paper
2017-01-0357
Dattaprasad Lomate, Asim Tewari, Prashant Date, Manoj R Ukhande, Girish M Shegavi, Raj Kumar Prasad Singh
Abstract The application of induction hardening treatment plays a vital role for enhancing fatigue life of various automotive components. This will incorporate compressive residual stresses in the component at significant extent. In this paper, wide range of experiments have been carried out on Rotating Bending Fatigue (RBF) specimens made from 38MnVS6 micro alloyed steel with induction hardening up to three different case depths. The set of specimens are fatigue tested at fully reverse loading condition using rotating bending fatigue testing machine. Based on this study a surface treatment factor is evaluated. This surface treatment factor is used as an input for evaluating precise fatigue life of the specimen using FEA packages. The fatigue life evaluated using FEA is showing good agreement with the results obtained through tests on the actual specimens.
2017-03-28
Technical Paper
2017-01-0356
Matthias Hell, Rainer Wagener, Heinz Kaufmann, Tobias Melz
Abstract In vehicle design and engineering, the fatigue of materials is a size-dependent phenomenon, which occurs in every safety-relevant component. An inaccurate fatigue assessment, neglecting relevant influencing factors, may therefore either lead to considerable safety risks or to a significant oversizing of the component. Due to the size dependency of the microstructure and the related deformation and fatigue mechanisms, the fatigue life estimation requires an understanding of the cyclic material behavior as well as the damage mechanisms of materials on different scales. In this respect, local strain-based fatigue design concepts are advantageous for the estimation of the fatigue properties of components with arbitrary size and geometry, because the applicable material models allow an implementation of a realistic cyclic material behavior and a relation to different fatigue damage mechanisms in the elastic and the elastic-plastic load regime.
2017-03-28
Technical Paper
2017-01-0254
Sudeep Chavare, Kevin Thomson, Nitin Sharma
Abstract Use of parametric approach to optimize CAE models for various objectives is a common practice these days. In addition to load members, the connection entities such as welds and adhesives play an important role in overall performance matrix. Hence adding the connection entities to the pool of design variables during an optimization exercise provide additional opportunity for design exploration. The method presented in this paper offers a unique approach to parameterize adhesive lines by evaluating the possibility of using structural adhesives as intermittent patches rather than continuous lines. The paper discusses two optimization studies 1) structural adhesive patches along with spot weld pitch as design variables, and 2) structural adhesive patches with gage variables. These studies include the Body in White (BiW) and Trimmed Body in White (TBiW) assessments.
2017-03-28
Technical Paper
2017-01-0255
Malli Kartheek Yalamanchili, Nitin Sharma, Kevin Thomson
Abstract The crashworthiness of body-in-white (BIW) plays a vital role in full vehicle crash performance. The structural integrity of BIW is controlled via strength of the spot welds and adhesives that are the primary entities to join sheet metal. The number of welds and amount of adhesives in the entire BIW directly affects the cost and the cycle time of the BIW; which makes them a good candidate for optimization. However optimization of the welds and/or adhesives not only reduces the number of connections but also provides the opportunity to improve the structural performance and mass saving by placing them optimally for the structural responses. This paper discusses the optimization of full vehicle structural performance for the small overlap crash event using the length of adhesives in the BIW as parameters. Included in the study were length of the adhesives and gage variables, defined in the front-end structure of the vehicle.
2017-03-28
Technical Paper
2017-01-0145
Edward Palmer, Wilko Jansen
Abstract In order to specify a brake system that will have robust performance over the entire range of expected vehicle drive cycles it is vital that it has sufficient thermal inertia and dissipation to ensure that component temperatures are kept within acceptable limits. This paper presents a high fidelity CAE (computer aided engineering) technique for predicting the temperature of the front brake and the surrounding suspension components whilst installed on vehicle. To define the boundary conditions the process utilizes a coupled unsteady CFD (computational fluid dynamics) and thermal solver to accurately predict the convective heat transfer coefficients across a range of vehicle speeds. A 1-D model is used to predict the brake energy inputs as well as the vehicle speed-time curves during the drive cycle based on key vehicle parameters including wide-open-throttle performance, drive train losses, rolling resistance, aerodynamic drag etc.
2017-03-28
Technical Paper
2017-01-0409
Divyanshu Joshi, Anindya Deb, Clifford Chou
Abstract It is recognized that there is a dearth of studies that provide a comprehensive understanding of vehicle-occupant system dynamics for various road conditions, sitting occupancies and vehicle velocities. In the current work, an in-house-developed 50 degree-of-freedom (DOF) multi-occupant vehicle model is employed to obtain the vehicle and occupant biodynamic responses for various cases of vehicle velocities and road roughness. The model is solved using MATLAB scripts and library functions. Random road profiles of Classes A, B, C and D are generated based on PSDs (Power Spectral Densities) of spatial and angular frequencies given in the manual ISO 8608. A study is then performed on vehicle and occupant dynamic responses for various combinations of sitting occupancies, velocities and road profiles. The results obtained underscore the need for considering sitting occupancies in addition to velocity and road profile for assessment of ride comfort for a vehicle.
2017-03-28
Technical Paper
2017-01-0401
Ye Yuan, Junzhi Zhang, Yutong Li, Chen Lv
Abstract As the essential of future driver assistance system, brake-by-wire system is capable of performing autonomous intervention to enhance vehicle safety significantly. Regenerative braking is the most effective technology of improving energy consumption of electrified vehicle. A novel brake-by-wire system scheme with integrated functions of active braking and regenerative braking, is proposed in this paper. Four pressure-difference-limit valves are added to conventional four-channel brake structure to fulfill more precise pressure modulation. Four independent isolating valves are adopted to cut off connections between brake pedal and wheel cylinders. Two stroke simulators are equipped to imitate conventional brake pedal feel. The operation principles of newly developed system are analyzed minutely according to different working modes. High fidelity models of subsystems are built in commercial software MATLAB and AMESim respectively.
2017-03-28
Technical Paper
2017-01-0375
Ligong Pan, Seung Hyun Jung, Sushanth Ramavath, Mohamed El-Essawi, Randall Frank, Jiawei Qin, Ramarajan Ilankamban, Yuan Yao, Homa Torab, Yuzhao Song, Jim Alanoly
Abstract Over the past decades, Computer Aided Engineering (CAE) based assessment of vehicle durability, NVH (Noise, Vibration and Harshness) and crash performance has become very essential in vehicle development and verification process. CAE activity is often organized as different groups based on the specific attributes (durability, NVH and crash). Main reasons for this are the expertise required and the difference in the finite element software technologies (explicit vs implicit) used to perform and interpret various CAE analyses in each of the attributes. This leads to individual attribute team creating its own model of the vehicle and there is not much exchange of the CAE models between the attribute teams. Different model requirements for each attribute make model sharing challenging. However, CAE analyses for all attributes start with common CAD and follow the same sub-process in vehicle development cycle.
2017-03-28
Technical Paper
2017-01-0363
Karthik Ramaswamy, Vinay L. Virupaksha, Jeanne Polan, Biswajit Tripathy
Abstract Expanded Polypropylene (EPP) foams are most commonly used in automotive applications for pedestrian protection and to meet low speed bumper regulatory requirements. In today’s automotive world the design of vehicles is predominantly driven by Computer Aided Engineering (CAE). This makes it necessary to have a validated material model for EPP foams in order to simulate and predict performance under various loading conditions. Since most of the automotive OEMs depend on local material suppliers for their global vehicle applications it is necessary to understand the variation in mechanical properties of the EPP foams and its effect on performance predictions. In this paper, EPP foams from three suppliers across global regions are characterized to study the inter-supplier variation in mechanical properties.
2017-03-28
Technical Paper
2017-01-0360
Guangtian Gavin Song, Joe Peters, Steven Hopson, Adrian Jordan
Abstract Vehicle chassis mounted cantilevered components should meet two critical design targets: 1) NVH criterion to avoid resonance with road noise and engine vibration and 2) satisfied durability performance to avoid any incident in structure failure and dysfunction. Generally, two types of testing are performed to validate chassis mounted cantilevered component in the design process: shaker table testing and vehicle proving ground testing. Shaker table testing is a powered vibration endurance test performed with load input summarized from real proving ground data and accurate enough to replicate the physical test. The proving ground test is typically performed at critical milestones with full vehicles. Most tests are simplified lab testing to save cost and effort. CAE procedures that virtually replicate these lab tests is even more helpful in the design verification stages.
Viewing 1 to 30 of 2994

Filter