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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
Technical Paper
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
2017-01-0403
Guangqiang Wu, Huwei WU
Experimental program and considerations, frequency characteristics, subjective and objective sound quality evaluation and 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 experiment schemes, including experimental operating conditions, vibration acceleration sensor and microphone arrangements and especial considerations in experiments, were introduced in detail. Secondly, through coherence analysis in frequency domain and time-frequency analysis in time-frequency domain, broadband characteristics of manual transmission gear rattle vibro-impact and frequency range of 350~4500Hz were concluded on vehicle idling condition and creeping condition.
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
2017-01-1056
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
2017-01-1062
Abdelkrim Zouani, Gabriela Dziubinschi, Vidya marri, Simon Antonov
In modern automotive engines, Variable Displacement Oil Pump (VDOP) is becoming the pump of choice to reduce friction and deliver stringent fuel economy. However, this pump creates pressure ripples, at the outlet port during a complete 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 presents an optimization method intended to identify the best possible spacing for the conventional 7-vanes and 9-vanes oil pumps. The method integrates a Matlab based oil pressure trace model into Mode Frontier computation platform. Bench tests are performed on several pumps with different vane spacing to measure the harmonics of the pressure ripples at the pump outlet in order to validate the results of the optimization study.
2017-03-28
Technical Paper
2017-01-0420
Prashant Khapane, Sumiran Lohani
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. The durability of engine mounts is a concern due to their susceptibility to wear and failure owing to high vibrational inputs. 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 engine mount designs. For the particular example considered here, 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
2017-01-1317
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
2017-01-1064
Mustafa Yıldırım
Engine system is getting smaller in time and getting more powerful engine is main purpose of many OEMs. While engines are getting more powerful, by the time, it is also getting smaller and less stiff. Smaller engines with high power means, engine vibrates more and so generates more noise.Thus engine structure and also engine main components should be design 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 also changing piston mass, conrod lenght and balancing parameters. Optimisation tool is used to obtain most robust design in terms of nvh.The combination of both engine structure and combustion is chosen to reduce vibration.
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
2017-01-1053
Satoshi watanabe, Yuji Miyata, Yosuke Ogata, Vincent Ivosic
Adoption of idling stop systems continues to increase even in non-hybrid vehicles with conventional engines in order to enhance fuel economy. Engine restart vibration occurs when returning from idling stop, so it is more frequent than the vibration that occurs during normal engine start-up, and engine restart vibration becomes more noticeable. Investigation is needed in the initial stages of vehicle development to predict the accurate level of engine restart vibration. This study presents a case of using the model-based development (MBD) process for engine restart vibration from the initial stages of development. 1. The new evaluation method of engine restart vibration: This uses the frequency weighting and the fouth power vibration dose values (VDV) prescribed by ISO 2631-1. They are applied by multiplying the seat vibration acceleration measured during restart. The obtained VDV in each direction are used as the engine restart vibration evaluation values. 2.
2017-03-28
Technical Paper
2017-01-1126
Yu Mao, Shuguang Zuo, xudong wu
Due to coupling of in-wheel motor and wheel/tire, the electric wheel system is different from the tire suspension system of internal combustion engine vehicles both in the excitation source and structural dynamics. Therefore emerging dynamics issues of electric wheel arouses attention. Aiming at longitudinal vibration problem of electric wheel system in the starting condition, vector control system of permanent synchronous hub motor considering dead-time effect of the inverter is primarily built. The transient change features and ripple features of electromagnetic torque in the starting condition with successive acceleration are revealed. Based on rigid ring model and dynamic tire/road interface, coupled longitudinal-torsional vibration model of electric wheel system is then established and inherent characteristics of this model are analyzed. The vibration responses of electric wheel system are simulated by combining electromagnetic torque and vibration model.
2017-03-28
Technical Paper
2017-01-0442
Harchetan Singh Aneja, Manas Tripathi, Harmeet Singh, Aashish Parmar
With increase in customer expectations for a quiet and comfortable ride, it has become the need of the hour for automobile manufacturers to continuously 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 this 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 motor driven component. The rotating parts (rotor, etc.) produce vibrations that may traverse to tank body & subsequently the 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, noise may also be produced by fuel flow pulsations if transferred through the piping to the 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
2017-01-1058
L V Pavan kumar Maddula, Ibrahim Awara
Increased focus on Fuel efficiency and vehicle emissions has led the automotive industry to look into low weight alternative designs for power train system components. These new design changes pose challenges to vehicle attributes like NVH, durability, etc. Further, the requirement of high power applications produces further complexities. The present work explains how a potential design change of drive shafts driven by a desire to reduce weight and cost can lead to NVH problems caused by drive shaft resonances and explains how using multiple dynamic vibration absorbers(DVA) could solve those issues to meet customer expectation while improving efficiency. This work-stream also highlights the possibility and implications of combining multiple dampers in to a single lower weight vibration absorber.
2017-03-28
Technical Paper
2017-01-0439
Joydeep Chatterjee, Yuva Kishore Vaddi, Chetan Prakash Jain
In urban driving conditions, the steering vibration feel plays a major role with the customer spending a significant amount of time behind the steering wheel. Considering the urban drive at Indian roads, 1000~1500rpm 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 feel. 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 identified.
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
2017-01-1125
Victor Baumhardt, Valdinei Sczibor
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 consist of a solid bar with joints at each extreme, however, Depending of its 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. The aim of this study is to propose an optimal halfshaft profile for a solid shaft to be machined from a rough bar, pursuing the lowest frequency the possible for the first bending mode by changing its diameter and, as a consequence, the mass and bending stiffness at appropriate regions.
2017-03-28
Technical Paper
2017-01-1330
Youssef Ziada, Juhchin Yang, David DeGroat-Ives
Due to decreased development cycle timing, designing components for manufacturability has never been as important. Assessing manufacturing feasibility has therefore become an increasingly important part of new product engineering. This manufacturing feasibility is conventionally assessed based on static stiffness of components and fixture assemblies. However, in many operations, excess vibration represents the actual limitation on processing a workpiece. Limits on how far into components a tool can reach or the amount of processing time required to machine a feature is commonly decreased significantly due to vibration. Significant time is spent resolving these vibration problems during product launches. Depending on the machining configurations these vibrations can be due to the part & work support structure or due to the tooling & spindle assembly. This paper presents approaches for predicting the dynamic flexibility for either of these assemblies using purely analytical approaches.
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
2017-01-0405
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
2017-01-0446
Xiao Chuan Xu
Aiming at the variable displacement oil pump, the modal and noise were studied, and structural optimization and test verification were carried out. The modal analysis of the variable displacement oil pump was carried out by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. Sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment. The modal of the variable displacement oil pump was analyzed by ABAQUS. Three dimensional unsteady flow field in the variable pump was calculated by Pumplinx. The sound field was calculated by ACTRAN acoustic software. The NVH and comprehensive performance test of the oil pump was carried out by oil pump test bench and B&K PULSE vibration and noise test equipment.
2017-03-28
Technical Paper
2017-01-1231
Chun Tang, Natee Limsuwan, Nurani Chandrasekhar, Zhichun Ma, Jacob Krizan, Joel Hetrick PhD, 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.
2017-01-15
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2017-01-10
Technical Paper
2017-26-0196
Kopal Agarwal, Sandip Hazra, Vikas Kolage
Abstract Key on/off Vibrations plays an important role in the quality of NVH on a vehicle. Hence having a good KOKO in the vehicle is desirable by every OEM. The vibration transfer to the vehicle can be refined by either reducing the source vibrations or improving isolation. In this study, critical factors affecting KOKO vibration has been identified. Focus has been given on improving the KOKO by change in mounting system stiffness & stopper gap, and assuming other parameters as constant. The study highlights a new simulation approach using ADAMS View to help run a DOE for solving KOKO issue on vehicle. The contribution of C mount stiffness and stopper gap is shown through simulation results. The correlation between simulation & test results has been established by measuring rigid body modes and KOKO vibration on vehicle for a set of mount configuration. Test results show significant KOKO improvement with the mount configuration optimized through simulation.
2017-01-10
Technical Paper
2017-26-0210
Surinder Kumar, Harveen Talwar
Abstract With the development of automobile industry, customer awareness about NVH (Noise, Vibration and Harshness) levels in passenger vehicles and demands for improving the riding comfort has increased. This has prompted automobile OEMs to address these parameters in design stage by investing resources in NVH research and development for all components. Better NVH of Radiator Fan Module (RFM) is one of the parameters which contributes to cabin comfort. The basic objective of RFM is to meet engine heat rejection requirements with optimized heat transfer and air flow while maintaining NVH within acceptable levels. The rotating fan (generally driven by an electric motor), if not balanced properly, can be a major source of vibration in the RFM. The vibration generated thus, can be felt by customer through the vehicle body.
2017-01-10
Technical Paper
2017-26-0207
Dayal Mirthinti, Dinesh Sahrawat, Rohit Dang
Abstract In automobile, NVH has been playing an important role in defining the overall quality of the vehicle. Continuous efforts are being put in globally by engineers to make the travel experience as comfortable as possible for both commercial and passenger segment vehicles. The front wiping system being a critical safety feature in an automobile is one of the sources of structural vibrations/noise due to numerous moving child parts. Therefore, the layout of the wiper motor in the vehicle is an important aspect of Vehicle NVH. These vibrations and noise levels become more pronounced if the wiper motor is mounted inside the passenger compartment, a layout that is commonly seen in commercial vehicles. This paper focuses on measures to improve the NVH while having the layout of the wiping system inside the passenger compartment of the vehicle.
2017-01-10
Technical Paper
2017-26-0217
Arvind Kumar Yadav, Mayur Birari, Vilas Bijwe, Dayanand Billade
Abstract Crank train torsional vibration is an important aspect for design and development of Powertrain for NVH refinement and durability. Crank train torsional vibration parameters like angular acceleration of flywheel or twist, depends upon various design parameters like geometry of crankshaft, mass of flywheel, stiffness of clutch, mass of pulley etc. It also depends upon engine operating conditions like engine speed, engine load, combustion peak pressure and combustion pressure variation etc. Most of these parameters are decided by engine power, torque, engine architecture and packaging constraints. Addition of torsional vibration damper (TVD), which works on the principle of tuned dynamic absorber, is commonly deployed design solution to control the torsional vibrations as well as stresses (to improve durability of crank train) induced in crank train assembly at specified modal frequency.
2017-01-10
Technical Paper
2017-26-0215
Kodali Ajay Krishna, Sanjeev Patil
Abstract In today's competitive automobile marketplace with reduced vehicle development time and fewer prototypes/tests, CAE is playing very crucial role in vehicle development. Automobile environment demands ever improving levels of vehicle refinement. Performance and refinement are the key factors which can influence the market acceptance of vehicle. Driveline is one of the key systems whose refinement plays critical role in improved customer satisfaction. Because of the virtue of the driveline functionality, driveline induced noise and vibration are the most common issues in the AWD vehicle development programs. Refinement of the drive line needs complicated nonlinear full vehicle CAE MBD models for the evaluation of driveline induced noise and vibration responses at different operating conditions [1]. In this paper a simplified approach is adapted for solving the Noise & Vibration issue which has been identified at the prototype testing level of an AWD vehicle development.
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