Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 2239
2015-10-04
Event
The session focusses on the fundamentals of the interaction on the sliding surface and associated friction induced vibrations. From nanoscale interactions of the contacts on the sliding interface to macroscopic methodology to diminish friction induced vibrations, this session comprises new findings and discussion toward a step forward to full understanding of the friction and brake induced vibration.
2015-06-24
Event
This session covers noise and vibration sources and paths within a vehicle (automobiles, trucks and recreational vehicles). Example of noise sources included are HVAC system, electric motor powered mechanisms and door closure and example of vibration sources are road and engine. Also included are Whole Body and Hand Arm Vibration experienced by professional drivers as well as acoustical design factors of audio, infotainment, and hands free devices.
2015-06-24
Event
This session covers noise and vibration sources and paths within a vehicle (automobiles, trucks and recreational vehicles). Example of noise sources included are HVAC system, electric motor powered mechanisms and door closure and example of vibration sources are road and engine. Also included are Whole Body and Hand Arm Vibration experienced by professional drivers as well as acoustical design factors of audio, infotainment, and hands free devices.
2015-06-23
Event
This session addresses the strategies and methods for implementing active noise and vibration control in a vehicle. It will cover sensors and transducers, feedback systems, control algorithms, software for active control, noise and vibration cancellation devices, noise and vibration measurement systems, and case studies.
2015-06-23
Event
This session is focused on the vehicle body interior noise issues caused by friction and/or impact due to the vibration of interfacing components. The papers in this session will investigate those issues through the best practice of analytical and experimental applications.
2015-06-23
Event
This session addresses the strategies and methods for implementing active noise and vibration control in a vehicle. It will cover sensors and transducers, feedback systems, control algorithms, software for active control, noise and vibration cancellation devices, noise and vibration measurement systems, and case studies.
2015-06-23
Event
This session addresses the strategies and methods for implementing active noise and vibration control in a vehicle. It will cover sensors and transducers, feedback systems, control algorithms, software for active control, noise and vibration cancellation devices, noise and vibration measurement systems, and case studies.
2015-05-11 ...
  • May 11-22, 2015 (6 Sessions) - Live Online
  • October 19-30, 2015 (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.
2015-04-14
Technical Paper
2015-01-1123
Jiangwu Zhang, Donghao Liu, Haisheng Yu
Torsional vibrations of the full hybrid electric vehicle driveline with a novel single-mode power-split transmission are investigated, in which three power sources, internal combustion engine (ICE), motor/generator 1 (MG1) and motor/generator 2 (MG2) are equipped. The compound planetary gear unit inside the transmission provides the driveline output with continuously variable gear ratios and serves as a power splitting device. Though very similar in configuration, the compound planetary gear used herein is a novel variation of Ravigneaux planetary gear set. MG1, MG2 and ICE are connected to the small sun gear (S1), the large sun gear (S2), the planetary carrier (C), respectively. The ring gear (R) is connected to the final reduction gear (FR), outputting tractions by the conventional differential (DF) to the right and left half shafts for the front wheels.
2015-04-14
Technical Paper
2015-01-1122
Kengo Yabe, Toru Inagaki, Takashi Kondo
Seat vibration when the vehicle is idling and when it is in motion has been reduced by using a floating seat that controls the resonance frequencies. The resonance frequency is controlled by replacing the structures of the seat-mounting unit with floating structures using rubber bushings. Partly replacing the mounting unit with floating structures makes it possible to control the resonance frequencies of the entire seat. The issue of balancing vibration reduction with strength and durability and crash safety performance due to fitting rubber bushings to the seat-mounting unit was addressed using stopper structures optimized for each type of input. To adopt a floating seat into an actual vehicle, the floating structure and conventional foot bracket are combined. This combined foot bracket not only makes it easy to assemble floating structure into the seat, but also makes it possible to keep the seat weight almost the same as a conventional seat.
2015-04-14
Technical Paper
2015-01-0430
Frédéric Kihm, Andrew Halfpenny, Benoît Beaum
Rotating machinery are found in every industry. While some machines are designed for constant-speed operation, others, such as the engines and transmission systems used in ground vehicles, are designed for varying speeds. The vibration environment of a varying speed engine or transmission system is best represented using a ‘Swept-Sine-On-Random’ vibration profile. The vibration profile comprises a mixture of deterministic signals, due to the engine rotation orders, superimposed on a background of Gaussian stochastic noise. Components mounted on these rotating machines are designed to survive these vibration levels over their entire service life. In the past many vibration test specifications were based on either a Power Spectral Density (PSD) function of random noise or as a series of discrete sine sweeps. The advantage of a Swept-Sine-On-Random profile is it is more characteristic of the real vibration environment.
2015-04-14
Technical Paper
2015-01-0666
Chenguang Li, Fue-Sang Lien, Eugene Yee, Mike Dong
A deeper understanding of the complex phenomenology associated with the flow induced noise and vibration in a dynamic valve is of critical importance to the automotive industry. To this purpose, a two-dimensional axisymmetric numerical model has been developed to simulate the complex processes that are responsible for the noise and vibration in a poppet valve (or poppet). More specifically, an Eulerian multiphase flow model, a dynamic mesh and a user-defined function are utilized within the ANSYS-FLUENT software system in order to facilitate the modeling of the complicated two-phase fluid-structure interaction problem associated with the generation of noise and vibration in a poppet valve. In this strongly coupled simulation framework, the poppet valve which is driven by spring and various dynamical fluid forces (e.g., viscous and pressure forces), is modeled as an under-damped vibration system.
2015-04-14
Technical Paper
2015-01-1195
Kiyotaka Maeda, Masashi Takahashi
To verify the appropriateness of the vibration test conditions of ISO 12405, we derived power spectrum densities and test durations as vibration test conditions by tailoring. Vehicles used for tailoring included two electric vehicles and one plug-in hybrid electric vehicle. Those vehicles were equipped with accelerometers and run on seven different types of road at different speeds, and the acceleration data that the battery packs received were recorded. The power spectrum densities for three axes that were derived from the obtained acceleration data were similar in form to the power spectrum densities of ISO 12405, and almost the same root mean square value of acceleration were obtained, confirming that they are appropriate. However, it has been suggested both experimentally and theoretically that the test duration for the Z-axis exceeds those of the X and Y axes.
2015-04-14
Journal Article
2015-01-1206
Manabu Yazaki
In recent years, the application of hybrid electric vehicle (HEV) technologies to a wide range of vehicles, from small to large vehicles and sedans to SUVs, has been expanding rapidly. Market demand for quiet drive is strong, and HEV systems are able to operate using motor drive alone, eliminating engine vibration and noise. To reduce torque fluctuation in order to reduce vibration and noise, distributed winding is used in the stators of the drive motors employed in many existing electric vehicles (EV) including HEV. However, because the coil ends of distributed windings are large, space for fitting is restricted. Concentrated winding is one method of reducing the size of the motor, because the coil ends can be made smaller. As winding resistance is lower in concentrated winding than in distributed winding copper loss is reduced, and the coils are effective under high-torque conditions.
2015-04-14
Journal Article
2015-01-0610
Guangqiang Wu, Wenbo Luan
During the launch of a car, severe torsional vibration sometimes may occur in its driveline due to somewhat the slipping of the clutch, its intuitive sense for an occupant is the longitudinal vibration of the vehicle, referred to as the launch shudder, whose characteristic frequency is from 5 to 25 Hz generally. As the main vibratory sources of the driveline and its crucial nonlinear components, variable stiffness and backlash of the gear meshing are considered, their impacts on launch shudder are analyzed in this paper. Conformal mapping, finite element method and regression method etc. are the main approaches to calculate the variable meshing stiffness of a gear pair. If this stiffness is get, it can usually be substituted for its approximate analytical expression, or just with finite harmonic terms, in Fourier series form into Ordinary Differential Equations(ODEs) to calculate the vehicle responses considering its nonlinearity.
2015-04-14
Journal Article
2015-01-0622
H. Metered, A. Elsawaf, T. Vampola, Z. Sika
Proportional integral derivative (PID) control technique is the most common control algorithm applied in various engineering applications. Also, particle swarm optimization (PSO) is extensively applied in various optimization problems. This paper introduces an investigation into the use of a PSO algorithm to tune the PID controller for a semi-active vehicle suspension system incorporating magnetorheological (MR) damper to improve the ride comfort and vehicle stability. The proposed suspension system consists of a system controller that determine the desired damping force using a PID controller tuned using PSO, and a continuous state damper controller that estimate the command voltage that is required to track the desired damping force. The PSO technique is applied to solve the nonlinear optimization problem to find the PID controller gains by identifying the optimal problem solution through cooperation and competition among the individuals of a swarm.
2015-04-14
Technical Paper
2015-01-1326
Sivanandi Rajadurai, Guru Prasad Mani, Kavin Raja, Sundaravadivelu Mohan
Generation of discretization with prescribed element sizes are adapted to the geometry. From Rules of thumb, for a complicated geometry it is important to select the reasonable element order, shapes and size for accurate results. In order to that, this paper describes the influence of elemental algorithm of the catalytic converter mounting brackets. Brackets are main source of mounting of various systems mainly intake and exhaust in the engine .In exhaust hot end system, bracket designs play a vital role because it has to withstand heavy structural vibrations without isolation combined with thermal loads. Bracket design and stiffness determines the whole Catalytic converter system's rigidity. So, here discretization of converter brackets by linear and parabolic elements is studied with different elements types and compared.
2015-04-14
Technical Paper
2015-01-0212
Mohamed El Morsy, Gabriela Achtenova
Condition monitoring is used to increase machinery availability and machinery performance, whilst reducing consequential damage, increasing machine life, reducing spare parts inventories, and reducing breakdown maintenance. An efficient condition monitoring system provides early warning of faults by predicting them at an early stage. When a localized fault occurs in gears, the vibration signals always exhibit non-stationary behavior. The periodic impulsive feature of the vibration signal appears in the time domain and the corresponding gear mesh frequency (GMF) emerges in the frequency domain. However, one limitation of frequency-domain analysis is its inability to handle non-stationary waveform signals, which are very common when machinery faults occur. Particularly at the early stage of gear failure, the GMF contains very little energy and is often overwhelmed by noise and higher-level macro-structural vibrations.
2015-04-14
Technical Paper
2015-01-1558
Amir Kharazi, Edward Duell, Austin Kimbrell, Ann Boh
Unsteady flow over automotive side-view mirrors may cause flow-induced vibrations of the mirror assembly which can result in blurred rear-view images, adversely affecting marketability and driver safety, as well as customer comfort and quality perception. Prior research has identified two mechanisms by which aerodynamically induced vibrations are introduced in the mirror. The first mechanism is unsteady aero pressure loading on the mirror face due to the unsteady wake, causing direct vibration of the mirror glass. The second mechanism, and the focus of this study, is a fluctuating loading on the mirror housing caused by an unsteady separation zone on the outer portion of the housing. A time-dependent Computational Fluid Dynamics (CFD) methodology to correctly model mirror wake behavior, and thereby predict flow-induced mirror vibration to improve performance estimations, was developed.
2015-04-14
Technical Paper
2015-01-1644
Huan Li, Ying Huang, Gang Li, Yongguang Yang
Key Words Diesel engine; Cylinder-by-cylinder variations; Cylinder-by-cylinder control; Torsional vibration Research Objective During the engine working process, the differences of each cylinder’s fuel injection quantity and the manufacturing deviations of mechanical parts will lead to cylinder-by-cylinder variations. It will bring about a large torsional vibration angular displacement of low-frequency and large fluctuation of the engine speed, especially in the idle condition. As a result, it brings down the engine performance and shortens the lifetime of the engine. In order to reduce the bad influences coming with the cylinder-by-cylinder variations, a detection method and an control algorithm of the variations need to be proposed. Methodology The traditional detection methods and control algorithms of cylinder-by-cylinder variations have been researched through literature survey.
2015-04-14
Technical Paper
2015-01-1504
WeiNing Bao
A ball screw regenerative shock absorber was designed for the relief of the vehicle vibration and the energy recovery of the vehicle vibration. The effect of its main parameters on the suspension system was numerically analyzed. According to the principle of the ball screw regenerative suspension system, a mathematical model of the ball screw regenerative shock absorber was established regarding the ball screw rotational inertia, the motor rotational inertia, the screw lead and the radius of the screw nut. A suspension dynamic model based on the ball screw regenerative shock absorber was developed combining the road model and the two-degrees-of-freedom suspension dynamic model.
2015-04-14
Technical Paper
2015-01-1671
Mohamed El Morsy, Gabriela Achtenova
In this paper, a fault in rolling bearing is diagnosed using time waveform analysis. In order to verify the ability of time waveform analysis in fault diagnosis of rolling bearing, an artificial fault is introduced in vehicle gearbox bearing: an orthogonal placed groove on the inner race with the initial width of 0.65 mm approximately. The faulted bearing is a roller bearing located on the gearbox input shaft – on the clutch side. An optimal Morlet Wavelet Filter and autocorrelation enhancement are applied in this paper. First, to eliminate the frequency associated with interferential vibrations, the vibration signal is filtered with a band-pass filter determined by a Morlet wavelet whose parameters are optimized based on maximum Kurtosis. Then, to further reduce the residual in-band noise and highlight the periodic impulsive feature, autocorrelation enhancement is applied to the filtered signal.
2015-04-14
Technical Paper
2015-01-1673
Seunghyun Lee, Yoonwoo Lee, Sungmoon Lee, Han Ho Song, Kyoungdoug Min, Hoimyung Choi
In this study, the correlation between the maximum heat release rate and the vibration of the diesel engine block was derived, and a methodology for determination of maximum heat release rate was presented. In order to investigate and analyze the correlation, the bench test and the real road vehicle test were carried out with a 1.6 l diesel engine. By varying the engine speed, load and main injection timing, the vibration signals were measured on engine block and was analyzed through continuous wavelet transform. It is shown that the maximum heat release rate had stronger correlation with magnitude of vibration rather than peak in-cylinder pressure and maximum in-cylinder pressure rise. A specific bandwidth, vibration signal of 0.1~2 kHz, was affected by the variation of heat release rate. The vibrations excited by combustion were lasted over 50 CAD, however, the signals in period of 35 CAD after start of injection had dominant effect on maximum heat release rate.
2015-04-14
Technical Paper
2015-01-1675
Yongfu Chen, Zhengfei Tang, Peijun Xu, Yunqing Zhang
A method for dynamic analysis and design of Powertrain Mounting System(PMS) is developed with the aim of reducing the vibration of the PMS, which is very significant to improve ride comfort. A nine degrees of freedom(DoF) dynamic model is established, including a powertrain and a chassis. The dynamic stiffness of the mounting is taken as the design parameter. Decreasing the dynamic force between the powertrain and the frame is the optimization objective. The initial values of the dynamic stiffness are obtained by finite element analysis. Due to the frequency dependence of dynamic stiffness, the dynamic stiffness is optimized at lower frequency section and high frequency section respectively. In addition, the deformation of the mounting under the gravity of powertrain is limited, which further determines the range of dynamic stiffness.
2015-04-14
Technical Paper
2015-01-1668
Chetankumar Patel, Nachiketa Tiwari, Avinash Kumar Agarwal
High viscosity of vegetable oil causes problems while using them as alternate fuel for compression ignition engines. There is a need to reduce the viscosity before using them as engine fuel. Preheating and pre-treating of vegetable oils using waste heat of exhaust gases is one of the techniques, which reduces the viscosity and makes it possible to use as alternate fuel for some niche applications, without major modifications in the engine hardware. There are several applications in developing countries such as decentralised power generation, agricultural engines, and water pumping engines, where vegetable oils can play a significant role as an alternate fuel. In present investigations, performance, combustion, emission characteristics of an engine using preheated Jatropha oil (J100) and 20% blend of Jatropha oil with mineral diesel (J20) have been evaluated at a constant speed (1500 rpm) in a single cylinder four stroke direct injection diesel engine.
2015-04-14
Technical Paper
2015-01-1670
Can Tao, Hengjia Zhu, Peijun Xu, Yunqing Zhang
Hydraulic Engine Mount (HEM) is widely used in vehicle Powertrain Mounting System (PMS) for vibration isolation. The dynamic performances of an HEM are strongly frequency dependent. A Five-Parameters Fractional Derivative model is used to describe the dynamic properties of a HEM. A 1/4 and 1/2 car model are applied to evaluate the effect of frequency-dependent dynamic stiffness which using measured data of a typical hydraulic engine mount. The excitations from engine and road are considered in the simulation. The generalized- method is presented to solve the vehicle model with Five-Parameters Fractional Derivative model.
2015-04-14
Technical Paper
2015-01-0625
Manfred Baecker, Axel Gallrein, Michael Roller
Abstract The tire plays a fundamental role in the generation of acoustically perceptible driving noise and vibrations inside the vehicle. An essential part of these vibrations is induced by the road excitation and transferred via the tire into the vehicle. There are two basic ways to study NVH behavior: Simulations in time and frequency domains. The system can be simulated using a transient simulation method with the disadvantage of high simulation and process turnaround times. Alternatively, a linearization around a stationary state is performed and solved in frequency domain with fast numerical schemes. Modelling the tire transfer behavior in frequency domain requires special attention to the rotation of the tire. This paper shows the approach taken by the authors to include the transfer behavior in the frequency range up to 250 Hz from geometric road excitations to resulting spindle forces in frequency domain. Special care has been used in the modelling of local road excitations.
2015-04-14
Technical Paper
2015-01-0615
Li Jie, Wang Wenzhu, Gao Xiong
Abstract In order to study the influence of body flexibility on the truck ride comfort, a 4 DOF half vibration model of truck based on the motion synthesis between rigid body and body flexibility is established using elastic beam theory of equal section with both free ends. At the same time, a corresponding 2 DOF rigid vibration model is also built. The frequency response functions of system and response variables of two models are derived based on front wheel. The power spectral densities and the root mean square values of body acceleration, dynamic deflections and relative dynamic loads are obtained. By comparing the simulation results of rigid-elastic model and rigid model, it shows that body flexibility has a great impact on truck ride comfort and it cannot be ignored.
2015-04-14
Journal Article
2015-01-1088
Tomohiko Usui, Tomoya Okaji, Tatsuya Muramatsu, Yoshiyuki Yamashita
Abstract By optimizing parameters related to damping performance and adopting a layout that incorporates the turbine into the damper components, a “Turbine Twin-Damper” lock-up damper was developed that achieves both damping performance and compactness. To reduce losses in the fluid flow channel, a smaller torus was developed that reduce the width of the torus by about 30%.Through the combination of this Turbine Twin-Damper and smaller torus, attenuation of the torque fluctuation transmitted to the transmission to 1/2 or less compared to a conventional product was achieved without increasing the overall width of the torque converter. As a result, the engine speed at cruise fell by 400rpm, and fuel economy improved.
Viewing 1 to 30 of 2239

Filter

  • Range:
    to:
  • Year: