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Viewing 1 to 30 of 2463
2017-06-05 ...
  • June 5-16, 2017 (6 Sessions) - Live Online
  • December 4-15, 2017 (6 Sessions) - Live Online
Training / Education Online Web Seminars
Finite Element Analysis (FEA) has been used by engineers as a design tool in new product development since the early 1990's. Until recently, most FEA applications have been limited to static analysis due to the cost and complexity of advanced types of analyses. Progress in the commercial FEA software and in computing hardware has now made it practical to use advanced types as an everyday design tool of design engineers. In addition, competitive pressures and quality requirements demand a more in-depth understanding of product behavior under real life loading conditions.
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.
2017-04-05
Event
This session addresses transmission noise, vibration, rattle issues and design solutions.
2017-03-28
Technical Paper
2017-01-1553
Min Kyoo Kang, Jin Hong Kim, HyuckJin Oh, Wookjin Jang, Sangwoo Lee, Young Hwan Lee
This paper presents a transient nonlinear vibration analysis of a full-vehicle model. The full-vehicle model consists of a powertrain model, a trimmed body, a drive line, and front and rear suspensions with tires, and is driven by combustion forces and runs on a road surface. The fundamental purpose of the transient nonlinear full-vehicle simulation is to replicate customer’s experience in driving situation in the time domain and to understand real-time phenomena. By performing time-domain simulation, it is possible to capture nonlinear behavior of a vehicle such as preloads due to gravitational force, large deformation, and material nonlinearity which cannot be properly considered in the conventional steady state analysis due to intrinsic linearization process. In constructing a full-vehicle, validation process is essential. Validation process is applied with respect to the assembling sequence.
2017-03-28
Technical Paper
2017-01-0443
Yong Hyun Nam, Gwansik Yoon
The sound induced by a closing door is determined by the various components like door latch, door module, door glass installed within the door area. The key components vibrate due to the force from the closing door, and the combined vibration caused by the components determines the sound from the door. In particular, when the door is closed with the door glass down, the vibration and noise of the door glass are louder than those of any other component; this is called door glass rattle - attributed to the loss of the door glass support point. This study not only evaluates the rattle influence level of a door glass support but also introduces an approach to reduce glass rattle noise by using sealing components. 1. Study on Minimization of Vibration A jig was constructed to evaluate the level of influence of the rattle of a door glass support.
2017-03-28
Technical Paper
2017-01-1136
Jack S.P. Liu, Natalie Remisoski, Javed Iqbal, Robert Egenolf
Automotive vehicles equipped with Cardan joints may experience a low frequency vehicle launch shudder vibration (5-30Hz) and a high frequency driveline moan vibration (80-200Hz) under operated angles and speeds. The Cardan joint introduces a 2nd order driveshaft speed variation and a 4th order joint articulation torque (JAT) causing the vehicle shudder and moan NVH issues. Research on the Cardan joint induced low frequency vehicle shudder using MBS method has been attempted. A comprehensive MBS method to predict the Cardan joint induced high frequency driveline moan vibration is yet to be developed. This paper presents a hybrid Multi-Body System (MBS) and FEA approach to predict the Cardan joint induced high frequency driveshaft moan vibration. The CAE method considers the elastically coupled driveshaft bending and engine block vibration due to Cardan joint excitation. Detailed driveshaft, joints, slip mechanism, differential, axle and wheel were modeled using a MBS modeling tool.
2017-03-28
Technical Paper
2017-01-0405
Tianqi Lv, Xingxing Feng, Peijun Xu, Yunqing Zhang
Several constitutive models which capture the amplitude and frequency dependency of filled elastomers are implemented for the conventional engine mounts of automotive powertrain mounting system (PMS). Firstly, a multibody dynamic model of a light duty truck is proposed, which includes 6 degrees of freedom (DOFs) for the PMS. Secondly, several constitutive models for filled elastomers are implemented for the engine mounts of the PMS, including nonlinear elastic model, frictional derivative viscoelastic model, general Maxwell chains, Coulomb-type friction, Berg’s friction model, common Kelvin-Voigt model etc. The nonlinear behavior of dynamic stiffness and damping of the mounts are investigated. Thirdly, simulations of engine vibration dynamics are presented and compared with these models and the difference between common Kelvin-Voigt model and other constitutive models are observed and analyzed.
2017-03-28
Technical Paper
2017-01-1023
Yaqun Jiang, C. Hsieh, Georg Festag, Masood Ahmed, William Jiang
Large axial displacement at the edge of a flywheel caused a clutch fail to disengage in high-speed rotation. To find out the root cause and solve the problem, a numerical procedure is proposed to investigate the vibration source and to understand dynamic behavior of the crank-train system. A simulation of the whole engine system including block, crankshaft, piston and connecting rod was performed with AVL/Excite. The baseline model was correlated with measurement. A comprehensive study was conducted for a set of flywheel and crankshaft models with different materials and unbalance masses. The contribution to flywheel wobbling of each vibration order was carefully investigated, and an optimal design was presented.
2017-03-28
Technical Paper
2017-01-1317
Luis Felipe Blas Martinez, Rodolfo Palma, Francisco Gomez, Dhaval Vaishnav, Francisco Canales
Liquid sloshing is an important issue in transportation, aerospace and automotive. Effects of sloshing in a moving liquid container can cause issues in: vehicle stability, safety, component fatigue, audible noise and comfort issues, fill level indication, etc. The sloshing phenomenon is a highly non-linear oscillatory movement of the free-surface of liquid inside a container (tank) under the effect of continuous or momentarily excitation forces. These excitation forces can result from sudden acceleration, braking, sharp turning or pitching motions. Due to the fluid inertia, waves are generated inside the tank, which can generate high pressure gradients over the tank surface when the fluid impacts the surface, causing the tank to vibrate resulting in fatigue loads. Structural fatigue in land vehicles is a major concern for loads in the 2-200 Hz range, but especially at the lower frequencies.
2017-03-28
Technical Paper
2017-01-1231
Chun Tang, Natee Limsuwan, Nurani Chandrasekhar, Zhichun Ma, Jacob Krizan, Joel Hetrick, Wei Wu
Abstract: Machine three phase current driven by PWM switching inverter in PM machine drive is not ideal sinusoidal, containing different levels of harmonics. The current harmonics have important impact on the electrical machine torque ripple which could translate into transmission and vehicle level noise vibration and harshness (NVH). In this work, the current waveforms were measured from dyno test at prescribed torque and speed levels, and the electric machine torque ripple was computed with the measured current. This paper will focus on the investigation of the current harmonics behaviors and features at various torque and speed conditions, the impact on torque ripple, and the possible mitigation method to reduce torque ripple.
2017-03-28
Technical Paper
2017-01-1229
Ken Yamamoto, Nobuyasu Sadakata, Hidetoshi Okada, Yusuke Fujita
Electric oil pumps (EOP) for automobiles are used to lubricate and cool moving mechanisms and supply oil pressure to components. Conventional EOPs consist of two separate units including a driver and a pump system comprised of a motor and a pump, which, as a result, impedes layout flexibility for vehicles. To overcome this shortcoming, we have developed an ECU-integrated oil pump in which a driver, a motor and a pump are incorporated as a single unit. In the course of the project, we focused on improving vibration resistance and developing a compact design. The first challenge was to improve vibration resistance because of the driver located in close proximity of the powertrain. Since the driver is installed on the motor unit via bus bars that are electrically welded, the joints of the driver and the bus bar become susceptible to vibration.
2017-03-28
Technical Paper
2017-01-1056
Rong Guo, Xiao-Kang Wei, Jun Gao
Commercial demands of comfort and stringent fuel economy have encouraged manufacturers to accommodate advanced technologies such as the Variable Displacement Engine (VDE), downsizing and so on in the new automotive models. Particularly, Active control engine mounts (ACMs) notably contribute to ensuring superior effectiveness in vibration suppression. This paper incorporates a PID controller into the active control engine mount system for inhabiting the transmitted force to the body. Furthermore, integrated time absolute error (ITAE) of the transmitted force is introduced to serve as the control goal for searching better PID parameters. Then the particle swarm optimization (PSO) algorithm is adopted for the first time to optimize the PID parameters in the ACM system. In the end, simulation results are presented for searching optimal PID parameters and validating the performance of the optimized PID control method.
2017-03-28
Technical Paper
2017-01-1059
Rong Guo, Jun Gao, Xiao-kang Wei
The active engine mount (AEM) is developed in automotive industry to improve overall NVH performance. The AEM is designed to reduce major order of engine vibration over a broad frequency range, therefore it is of vital importance to extract major order signals from vibration before the actuator of the AEM works. This paper focuses on a method of real-time extraction of the major order acceleration signals at the passive side of the AEM. Firstly, the transient engine speed is tracked and calculated, from which the FFT method with a constant sampling rate is used to identify the time-related frequencies as the frequency base. Then the major order signals in frequency domain are computed according to the certain multiple relation of the frequency base. After that, the major order signals of acceleration can be reconstructed in time-domain, which are proved accurate through offline simulation, compared with the given signal.
2017-03-28
Technical Paper
2017-01-0480
Mingde Ding
For structural application, composite parts structure is much more affected by load cases than steel part structure. Engine room bracket of EV, which is structural part and is used to bear Motor Controller, Charger and so on, has different load cases for different EV. Three commonest load cases that are Case 1: bearing 65kg (without suspension part), Case 2: bearing 68kg(including 3.5kg suspension part) and Case 3: bearing 70.1kg (including 5.6kg suspension part). According to topology optimization, structurel 1 was obtained, and then CAE analysis including (strength, stiffness and model) was carried out for abovement three load cases. For Case 1 and Case 2, the analysis result can meet the requirement. However, for Case 3, the stiffness and model analysis result can not satisfy the requirement. To meet the analysis result of Case 3, Structure 1 was optimized and structure 2 was obtained. The CAE analysis was conducted and the results can satisfy the requirements.
2017-03-28
Technical Paper
2017-01-1051
Hassan Nehme, Abdelkrim Zouani
Turbocharged engines constitute one of the strategies used by Ford Motor Company to deliver engines with improved fuel economy and performance. However, turbochargers exhibit many inherent NVH challenges that need to be addressed in order to deliver refined engines that meet customers’ expectations. One of these challenges is the turbocharger 1st order synchronous noise due to the interaction between the manufacturing tolerances of the rotating components and the dynamics of the rotor. This paper presents an analytical method to compute the turbocharger bearing forces and predict the 1st order synchronous noise and vibrations. The method consists of a fully coupled turbocharger rotor dynamic analysis in a flexible turbocharger housing structure; it predicts housing vibrations under various manufacturing tolerance conditions. The predicted vibrations of the turbocharger housing are compared to measured test data to demonstrate the validity of the analytical method.
2017-03-28
Technical Paper
2017-01-0439
Joydeep Chatterjee, Yuva Kishore Vaddi, Chetan Prakash Jain
Abstract In urban driving conditions, the steering vibration plays a major role for a customer, spending a significant amount of time behind the steering wheel. Considering the urban drive at Indian roads, 1000~1600rpm band becomes primary area of concern. In this paper, study has been conducted to define the target areas as well as its achievement in reference to given driving pattern on a front wheel powered passenger car for steering vibration. During the concept stage of vehicle development, a target characteristic of steering wheel vibration was defined based on the competitor model benchmarking and prior development experience. A correlated CAE model was prepared to evaluate the modification prior to prototype building and verification. Vibration level in all 3 degrees of freedom at the steering wheel location was measured in the initial vehicle prototypes and target areas of improvement are identified.
2017-03-28
Technical Paper
2017-01-0442
Harchetan Singh Aneja, Manas Tripathi, Harmeet Singh, Aashish Parmar
Abstract With the increasing expectation of customer for a quiet and comfortable ride, automobile manufacturers need to continuously work upon to improve automobile powertrain NVH. Today’s customer has become so aware of vehicle related noises that in-tank fuel pump noise is no exception to the checklist of evaluating cabin NVH. In-tank fuel pump, that is responsible for delivering the fuel from fuel storage tank to delivery rail, uses an electric driven motor. The rotating parts such as rotor, etc. produce vibrations that may traverse to tank body & subsequently vehicle body. Since noise is essentially an audible vibration at its root, these structure borne vibrations may be perceived as noise inside passenger cabin. Additionally, the noise may also be produced by fuel flow pulsations if transferred through piping to vehicle body. This paper focuses on various approaches to reduce the fuel pump generated noise heard inside passenger cabin.
2017-03-28
Technical Paper
2017-01-0445
Muthukumar Arunachalam, Arunkumar S, PraveenKumar Sampath, Abdul Haiyum, Yash Khakhar
In recent years, there is increasing demand for every CAE engineer on their confidence level of the virtual simulation results due to the upfront robust design requirement during early stage of an automotive product development. Apart from vehicle feel factor NVH characteristics, there are certain vibration target requirements at system or component level which need to be addressed during design stage itself in order to achieve the desired functioning during vehicle operating conditions. Vehicle passive safety system is one of which primarily consists of acceleration sensors, control module and air-bag deployment system. As the sensors act as the front-end of passive safety system and control module’s decision is based on these sensors signals, its mounting locations should meet the sufficient inertance or dynamic stiffness performance in order to avoid distortion in signals due to its structural resonances.
2017-03-28
Technical Paper
2017-01-0446
Xiao Chuan Xu, Xiuyong Shi, Jimin Ni, Jiaqi Li, Xiaochuan Xu Sr.
Abstract Oil pump is a critical part of engine lubrication system. The performance and efficiency of oil pump are greatly affected by vibration and noise, which would lead to the pump service life decreasing and pump body easily wearing. Hence the vibration and noise of oil pump is of great importance to study. In this paper, a FEA model of the variable displacement oil pump(VDOP) was established to carry on the modal and noise analysis, while the geometric structure was optimized with test verification. The modal analysis of VDOP was carried out by ABAQUS software, the 3-D unsteady flow field in VDOP was simulated by Pumplinx software, and the sound field was analyzed by ACTRAN acoustic module. Using a special oil pump test bench combined with B&K PULSE vibration and noise test equipment, the NVH and comprehensive performance experiment of the VDOP were carried out here.
2017-03-28
Journal Article
2017-01-1053
Satoshi Watanabe, Yuji Miyata, Yosuke Ogata, Vincent Ivosic
Abstract Idling stop systems are being increasingly adopted in conventional engine vehicles as well as hybrid electric vehicles to increase fuel efficiency. When the engine starts, body vibration occurs that is caused by the rigid body eigenvalues of the power plant during initial combustion. Engine restart vibration after an idling stop is caused by the input force from the transmission, and the reaction force from the drive shaft as well as the input force from the engine. This phenomenon occurs frequently when the engine is restarted from the idling stop, the vibration is increasingly annoying to passengers. Usually, the vehicle development process is carried out in accordance with the V process. The V process divides the vehicle development process into two stages. The first stage is called the vehicle design stage to determine the characteristic. The second stage is called the vehicle verification stage to verify the performance.
2017-03-28
Journal Article
2017-01-1126
Yu Mao, Shuguang Zuo, Xudong Wu
Due to coupling of in-wheel motor and wheel/tire, the electric wheel system of in-wheel motor driven vehicle is different from tire suspension system of internal combustion engine vehicle both in the excitation source and structural dynamics. Therefore emerging dynamic issues of electric wheel arouse attention. Longitudinal vibration problem of electric wheel system in starting condition is studied in this paper. Vector control system of permanent magnet synchronous hub motor considering dead-time effect of the inverter is primarily built. Then coupled longitudinal-torsional vibration model of electric wheel system is established based on rigid ring model and dynamic tire/road interface. Inherent characteristics of this model are further analyzed. The vibration responses of electric wheel system are simulated by combining electromagnetic torque and the vibration model. The results indicate that abrupt changes of driving torque will cause transient vibration of electric wheel system.
2017-03-28
Technical Paper
2017-01-1487
Russ Norton, Ben Bulat, Ahmed Mohamed
The RLM algorithm seeks to resolve the tradeoff of high damping rates required to control the loads and the need for lower damping forces to improve secondary ride. As the base active damping forces are increased to control the loads, ride benefits of the system are diminished. To ensure the best possible outcome, the team sought to reduce the tradeoffs by looking for a way to switch the damping force fast enough to manage the loads without affecting secondary ride. The RLM algorithm is designed to manage the road loads when driving through potholes. The algorithm detects the presence of a pothole based on individual suspension velocity and direction. When the wheel enters the pothole, the suspension velocity increases quickly while traveling downward (suspension rebound travel) into the pothole.
2017-03-28
Technical Paper
2017-01-0875
Valentin Soloiu, Jose Moncada, Martin Muinos, Aliyah Knowles, Remi Gaubert, Thomas Beyerl, Gustavo Molina
This paper investigates the performance of an indirect injection (IDI) diesel engine fueled with Bu25, 75% ultra-low sulfur diesel (ULSD#2) blended with 25% n-butanol by mass. N-butanol, derivable from biomass feedstock, was used given its availability as an alternative fuel that can supplement the existing limited fossil fuel supply. Combustion and emissions were investigated at 2000 rpm across loads of 4.3-7.2 bar indicated mean effective pressure (IMEP). Cylinder pressure was collected using Kistler piezoelectric transducers in the precombustion (PC) and main combustion (MC) chambers. Ignition delays ranged from 0.74 - 1.02 ms for both operated fuels. Even though n-butanol has a lower cetane number, the high swirl in the separate combustion chamber would help advance its premixed combustion. The heat release rate of Bu25 became initially 3 J/crank-angle-degree (CAD) higher than that of ULSD#2 as load increased to 7.2 bar IMEP.
2017-03-28
Journal Article
2017-01-0333
Kurt Munson, Frederic Kihm, Andrew Halfpenny
Finite Element Analysis (FEA)-based structural simulations are typically used to assess the durability of automotive components. Many parts experience vibration in use, and resonance effects are directly linked to many structural problems. In this case, dynamics must be included in the structural analysis. Dynamic FEA can be more realistic than static analysis, but it requires knowledge of additional characteristics such as mass and damping. Damping is an important property when performing dynamic FEA, whether transient or steady state frequency response, as it governs the magnitude of the dynamic stress response and hence durability. Unfortunately the importance of damping is often overlooked; sometimes a default damping value is erroneously assumed for all modes. Errors in damping lead to errors in the stress response, which in turn lead to significant changes in the fatigue life estimates.
2017-03-28
Technical Paper
2017-01-1064
Mustafa Yıldırım
Abstract Engine design is crucial in terms of NVH. It is the sources of vibration for a vehicle. Nowadays engine tends to being smaller and less stiff and more powerful according to predecessor. Small engines with high power is inherently generates extreme force and vibrations and accordingly generates more noise. Thus engine structure and also engine main components should be designed to prevent this vibration. There are two main sources: One of them is combustion and other is inertia loads. Due to this sources engine structure can cause severe vibration and accordingly this can cause noise via transmitting it into vehicle with both structure and airborne. This paper focused on to reduce engine vibration level with changing the combustion inputs such as cylinder pressure parameters and inertia parameters like piston mass, conrod length and balancing parameters. Design of experiment is used to obtain most robust case in terms of NVH.
2017-03-28
Journal Article
2017-01-0403
Guangqiang Wu, Huwei Wu
Abstract Experimental schemes, frequency characteristics, subjective and objective sound quality evaluation and sound quality prediction model establishment of a certain mass-production SUV (Sport Utility Vehicle, SUV) manual transmission gear rattle phenomenon were analyzed in this paper. Firstly, vehicle experiments, including experiment conditions, vibration acceleration sensor and microphone arrangements and especial considerations in experiments, were described in detail. Secondly, through time-frequency analysis, broadband characteristics of manual transmission gear rattle noise were identified and vibro-impact of gear rattle occurs in the frequency range of 450~4000Hz on the vehicle idle condition and the creeping condition. Thirdly, based on bandwidth filtering processing of gear rattle noise, subjective assessment experiments by a paired comparison method were carried out.
2017-03-28
Journal Article
2017-01-0420
Prashant Khapane, Sumiran Lohani
Abstract Vibration Isolation is the key objective of engine mounting systems in the automotive industry. A well-designed, robust engine mount must be capable of isolating the engine assembly from road-based excitations. Owing to high vibration inputs, engine mounts are susceptible to wear and failure. Thus, the durability of engine mounts is a cause for concern. A design validation methodology has been developed at Jaguar Land Rover using Multibody Dynamics (MBD) to enhance the prognosis of engine mount loads during full - vehicle durability test events. This paper describes the development of a virtual multi-axial simulation table rig (MAST Rig) to test virtual engine mount designs. For the particular example considered in this paper, a simple sinusoidal input is applied to the MAST Rig. The development of the virtual MAST Rig has been described including details of the modelling methodology.
2017-03-28
Technical Paper
2017-01-1058
L.V. Pavan Kumar Maddula, Ibrahim Awara
Abstract Increased focus on fuel efficiency and vehicle emissions has led the automotive industry to look into low weight alternative designs for powertrain system components. These new design changes pose challenges to vehicle attributes like NVH, durability, etc. Further, the requirement of high power applications produces even more complexities. The present work explains how a potential design change of half shafts driven by a desire to reduce weight and cost can lead to NVH problems caused by half shaft resonances and explains how using multiple dynamic vibration absorbers can solve the issue to meet customer expectation while improving efficiency. With the aid of Finite Element Analysis (FEA) & optimization software, interactions between multiple DVA’s on a system was understood and optimal damper parameters for effective damping was identified. The final DVA design was tested and verified on the vehicle for optimal attribute performance.
2017-03-28
Technical Paper
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya Marri, Simon Antonov
Abstract In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to enable reduction in friction and delivery of stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during oil pump shaft rotation, causing oscillating forces within the system and leading to the generation of tonal noises and vibrations. In order to minimize the level of noise, different porting geometries and vane spacing are used. This paper describes an optimization method intended to identify the best possible spacing of the vanes in the conventional 7-vanes, 9-vanes and 11-vanes oil pumps. The method integrates a Matlab routine with the modeFRONTIER software to create the required design space in order to perform a multi-objective optimization using a genetic algorithm. Results of this optimization method are discussed and a design guideline for the VDOP vane spacing is disclosed.
2017-03-28
Technical Paper
2017-01-1125
Victor Baumhardt, Valdinei Sczibor
Abstract Halfshafts are very important components from vehicle powertrain. They are the element responsible to transmit torque and rotation from transmission to wheels. Its most basic design consists of a solid bar with joints at each extreme. Depending of bar length, the natural frequency of first bending mode might have a modal alignment with engine second order, resulting in undesired noise on vehicle interior. Many design alternatives are available to overpass this particular situation, like adding dampers, use tube shafts or use link-shafts, however, all of them are cost affected. This study proposes an investigation to obtain an optimal profile for a solid shaft, pursuing the lowest possible frequency for the first bending mode by changing its diameter at specific regions. The study is divided in four main stages: initially, a modal analysis of a halfshaft is done at vehicle to determinate its natural frequency when assembled on vehicle.
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