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CURRENT
2016-04-20
Standard
J3001_201604
This procedure is applicable to modes from 500 and 13,000 Hz. The parameters measured with this procedure are defined as the damping factor, ξ for first nine vibration modes of the beam. The measurement will be done in free-free conditions and with temperature.
2016-04-14
Article
Manufacturing and service teams are discovering ways to use AR technology to handle complex systems like wire harnesses.
2016-04-13
Article
The nCode brand of durability, test, and analysis software by HBM introduces nCode VibeSys, a new data processing system designed to help acoustics and vibration engineers.
2016-04-11
Article
Automakers are increasingly employing digital crash test dummies made of zeroes and ones to take the big hits in virtual vehicles.
2016-04-05
Technical Paper
2016-01-1058
Naoki Toyama, Takashi Hoshi
Abstract The subject is technology for damping forced vibration in the multiplate wet clutches used in hybrid vehicle transmissions. As a predictive technique for forced vibration caused by the structure of the clutch, three-dimensional simulation was used in the present study to anticipate the modes of vibration that occur. Next, a one-dimensional simulation was created as a predictive technique for drivetrain torsional vibration from the engine to the driveshaft. The one-dimensional simulation created was used to extract the modes of operation that are severe with regard to forced vibration from target values for vibration anticipated from the vehicle body. The results obtained were used with three-dimensional simulation to change the clutch structure to provide greater latitude with regard to the target for forced vibration.
2016-04-05
Technical Paper
2016-01-1060
Arnab Ganguly, Niket Bhatia, Vikas Kumar Agarwal, Ulhas Mohite
Abstract With ride comfort in a motorcycle gaining significance, it is important to minimize vibration levels at the customer touch points. The reciprocating piston imparts rotary motion to the crankshaft which in turn induces unbalance forces and produces vibration in the vehicle, thus influencing the ride quality. Generally, the primary inertial forces are balanced by a combination of balancer body and crank web. However, being a commuter bike, a balancer body could not be accommodated due to cost and space constraints. In such scenario, the first order unbalance force cannot be completely eliminated but can only be redistributed by adding counterweight to the crankshaft. Proper distribution of these forces is required for optimum vibration levels at motorcycle touch sensitive points (TSP) such as handle bar, footrest etc.
2016-04-05
Technical Paper
2016-01-1061
Guiping Yue, Wenbo Niu, Jian Zhao, Dandan Kong, Yun Li, Hangsheng Hou
Abstract Gear whine noise impacts customer perception of vehicle interior quietness in general and sound quality in particular. It has been a frequently occurred annoying phenomenon during vehicle development and much discussed topic regarding transmission NVH refinement in automotive industry. This work pertains to a transmission gear whine issue encountered in prototype evaluations during a vehicle program development process. The effort centers itself on the optimization of transmission gear macroscopic and microscopic parameters to fix the issue which is deemed unacceptable for customers. Specifically, by using multi-body dynamics approach, this work carries out a transmission system whine noise simulation based on optimal gear macro parameter selection and micro tooth flank modification. The obtained results show that the proposed design changes could successfully resolve the issue, which is verified by subsequent test measurement and confirmed by subjective evaluations.
2016-04-05
Technical Paper
2016-01-1053
TL Balasubramanian, Vigneshwara Raja Kesavan, V Lakshminarasimhan, Vamsi Krishna Balla, Suresh Palani
Abstract This paper discusses various noise sources of cylinder head assembly and focuses on design options developed to reduce the cylinder head noise in a single cylinder, 110cc scooter engine. Various experimental procedures were used for identification and ranking of different noise sources. In case of air-cooled small engines, temperature effects are dominant and as a consequence certain noises stand out in hot condition causing severe noise discomfort. After identifying the reasons for abnormal cylinder head noise, countermeasure mechanisms for reducing unintended impacts of valve train/ rocker arm in the layout were developed. The side-effects due to introduction of these additional mechanisms are studied using performance metrics. It is essential to limit noise deterioration over time to increase customer satisfaction. Simulation cycles were developed to quantify the cylinder head noise deterioration using accelerated testing procedures.
2016-04-05
Technical Paper
2016-01-1040
Rostislav Hadas, Rolf Sauerstein, Radúz Zahoranský, Michael Stilgenbauer, Matthias Ruh
Abstract A new generation of gasoline engine turbochargers has been developed with a focus on high performance and excellent NVH characteristics, especially with regards to the wastegate control system. With the recent introduction of EU6 emission standards, there is a clear demand to precisely control the flow of exhaust gas through the turbine wastegate. Engine operational duty cycles measured on EU6 compatible vehicles have shown increased stresses on wastegate parts due to a higher amount of regulation strokes during operation. Recent developments in the compact design of exhaust systems together with high pressure pulsation forces acting on wastegate flaps constitute the main challenges facing turbo engineers in the effort to achieve customer durability while meeting NVH requirements. For the development of a new generation of wastegate control systems a unique load prediction model was duly developed.
2016-04-05
Technical Paper
2016-01-1349
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
Abstract In the current scenario, the major thrust is to simulate the customer usage pattern and lab test using virtual simulation methods. Going ahead, prime importance will be to reduce the number of soft tool prototype for all tests which can be predicted in CAE. Automotive door slam test is significantly complex in terms of prediction through simulation. Current work focuses on simulating the slam event and deriving load histories at different mounting locations through dynamic analysis using LSDyna. These extracted load histories are applied to trimmed door Nastran model and modal transient analysis is performed to find the transient stress history. This approach has a significant advantage of less computation time and stress-convergence with Nastran for performing multiple design iterations compared to LSDyna. Good failure correlation is achieved with the test using this approach.
2016-04-05
Technical Paper
2016-01-1348
Kenichi Higuchi, Fumihiko Toyoda, Hirohito Terashima, Shinji Ikeda, Eitaku Nobuyama
Abstract 1 There are two design challenges of the flow path switching valve in a three-stage variable discharge oil pump. The first is to obtain the required discharge pressure characteristics and the other is to prevent hydraulic vibration. Therefore, we established technologies to determine the shape of the valve and the valve housing that resolve these two challenges. The technology to obtain the required discharge pressure characteristics solves equations that are statically true, such as the equations for the equilibrium of forces and hydraulic orifice. The hydraulic vibration control technology derives a differential equation that takes transient behavior, including oil elasticity and inertia, into account first. Then, the derived equations are converted to a transfer function that indicates the valve behavior according to the input of oil pressure changes. And then the stability criterion is applied to judge whether hydraulic vibration occurs or not.
2016-04-05
Technical Paper
2016-01-1361
Abhijit Londhe, Vivek Yadav, SenthilKumar Kannaiyan, Krishnan Karthikeyan, Ganeshan Reddy
Abstract Reducing the vibrations in the drivetrain is one of the prime necessities in today’s automobiles from NVH and strength perspectives. The virtual drivetrain simulation methodology to predict the driveline induced excitations transmitted to vehicle is developed for three cylinder engine using Adams View. The obtained mount forces from Adams dynamic simulation is correlated with the measured test data at vehicle level and the good correlation is observed. Paper discusses on the methodology of virtual drivetrain using Adams view and the correlation of measured dynamic mount forces with simulation results. This correlation gives the confidence that the developed simulation methodology can be used to get the mount forces of different orders from drivetrain.
2016-04-05
Technical Paper
2016-01-1378
Takanori Ide, Kentaro Toda, Yasunori Futamura, Tetsuya Sakurai
Abstract Efficient method to solve large-scale eigenvalue problem in vibration is presented. NVH (Noise, Vibration and Harshness) performance is an important quality measure of vehicles. Therefore, the reduction of vibration is one of the key considerations of new automatic transmission design. In addition, reduction of product design time is another important requirement. Computer Aided Engineering (CAE) is becoming a more important methodology to reduce product design time. However, computational time of eigenvalue problem takes long. We propose parallel eigenvalue computation (Sakurai-Sugiura method) for large-scale eigenvalue problems. This method has a good parallel scalability according to a hierarchical structure of the method. As the demonstrative problem, we consider large-scale computation of eigenvalue problem for AISIN AW FWD automatic transmission.
2016-04-05
Technical Paper
2016-01-1300
Jacob Milhorn, Vincent Rovedatti, Richard DeJong, Gordon Ebbitt
Abstract Road tests on a pickup truck have been conducted to determine the acoustic loads on the back panel surfaces of the vehicle. Surface mounted pressure transducers arrays are used to measure both the turbulent flow pressures and the acoustic pressures. These measurements are used to determine the spatial excitation parameters used in an SEA model of the transmission loss through the back panel surfaces. Comparisons are made between tests on different road surfaces and at different speeds to identify the relative contributions of acoustic and wind noise.
2016-04-05
Technical Paper
2016-01-1311
Tsuyoshi Kanuma, Katsumi Endo, Fumiaki Maruoka, Hiroshi Iijima, Makoto Kawamura, Keisuke Nakazawa, Eiki Yanagawa
Abstract 1 The vane-type rotary compressor of a heating, ventilating, and air conditioning system (HVAC system) is simple and compact but may emit noise due to the collision between the vanes and the cylinder wall. Several studies have been conducted on this chattering noise, with a focus on the noise associated with the compressor revolution speed, temperature, suction pressure, and exhaust pressure. However, such investigations are not sufficient to reveal the behavior of the vane movement in its entirety. To minimize the chattering noise, the details of the mechanism of such vane-operating noise must be investigated by analyzing the behavior of the vanes as a function of time. The vanes move according to the balance between the front and rear pressures. This report describes a novel visualization technique with which to monitor the motion of a vane under given operating conditions. In addition, a method of measuring the pressure affecting the movement of the vanes is discussed.
2016-04-05
Technical Paper
2016-01-1309
Yingping Lv, Yongchang Du, Yujian Wang
Abstract In this paper, analysis methods for brake squeal including substructure modal composition analysis and substructure modal parameters sensitivity analysis are presented. These methods are based on a new closed-loop coupling disc brake model, where the coupled nodal pairs in each coupling interface are connected tightly. This assumption is different from other existing models in literatures, where the interface nodes are coupled through assumed springs. Based on this new model, two analysis methods are derived: Substructure modal composition analysis indicates the contribution of modes of each substructure to the noise mode; Substructure modal parameters sensitivity analysis indicates the sensitivity of the real part of system’s eigenvalue to component’s modal frequency and shape. Finally, the presented analysis methods are applied to analyse a high frequency squeal problem of a squealing disc brake.
2016-04-05
Technical Paper
2016-01-1313
Brian Pinkelman, Woo-Keun Song
Abstract Most methods of vibration analysis focus on measuring the level of vibration. Some methods like ISO-2631 weigh vibration level based on human sensitivity of location, direction, and frequency. Sound can be similarly measured by sound pressure level in dB. It may also be weighted to human frequency sensitivity such as dBA but sound and noise analysis has progressed to measure sound quality. The characteristic and the nature of the sound is studied; for example equal or near equal sound levels can provide different experiences to the listener. Such is the question for vibration; can vibration quality be assessed just as sound quality is assessed? Early on in our studies, vibration sensory experts found a difference in 4 seats yet no objective measurement of vibration level could reliably confirm the sensory experience. Still these particular experiences correlated to certain verbal descriptors including smoothness/roughness.
2016-04-05
Technical Paper
2016-01-1617
Yoshinobu Yamade, Chisachi Kato, Shinobu Yoshimura, Akiyoshi Iida, Keiichiro Iida, Kunizo Onda, Yoshimitsu Hashizume, Yang Gou
Abstract A wall-resolving Large Eddy Simulation (LES) has been performed by using up to 40 billion grids with a minimum grid resolution of 0.1 mm for predicting the exterior hydrodynamic pressure fluctuations in the turbulent boundary layers of a test car with simplified geometry. At several sampling points on the car surface, which included a point on the side window, the door panel, and the front fender panel, the computed hydrodynamic pressure fluctuations were compared with those measured by microphones installed on the surface of the car in a wind tunnel, and effects of the grid resolution on the accuracy of the predicted frequency spectra were discussed. The power spectra of the pressure fluctuations computed with 5 billion grid LES agreed reasonably well with those measured in the wind tunnel up to around 2 kHz although they had some discrepancy with the measured ones in the low and middle frequencies.
2016-04-05
Technical Paper
2016-01-1616
Keiichiro Iida, Kunizo Onda, Akiyoshi Iida, Chisachi Kato, Shinobu Yoshimura, Yoshinobu Yamade, Yoshimitsu Hashizume, Yang Guo
Abstract One-way coupled simulation method that combines CFD, structural and acoustical analyses has been developed aiming at predicting the aeroacoustical interior noise for a wide range of frequency between 100 Hz and 4 kHz. Statistical Energy Analysis (SEA) has been widely used for evaluating transmission of sound through a car body and resulting interior sound field. Instead of SEA, we directly computed vibration and sound in order to investigate and understand propagation paths of vibration in a car body and sound fields. As the first step of this approach, we predicted the pressure fluctuations on the external surfaces of a car by computing the unsteady flow around the car. Secondly, the predicted pressure fluctuations were fed to the subsequent structural vibration analysis to predict vibration accelerations on the internal surfaces of the car.
2016-04-05
Technical Paper
2016-01-1673
Long Chen, Shuwei Zhang, Mingyuan Bian, Yugong Luo, Keqiang Li
Abstract The in-wheel-motor (IWM) drive system has some interesting features, such as the vibration of this structure at low velocity. An explanation of this phenomenon is given in this paper by considering the dynamics performance of the in-wheel motor drive system under small slip ratio conditions. Firstly, a frequency response function (FRF) is deduced for the drive system that is composed of a dynamic tire model and a simplified motor model. Furthermore, an equation between the resonance velocity with the parameters of the drive system is obtained by combining the resonance frequency of this drive system with the fundamental frequency of the motor. The correctness of the equation is demonstrated through simulations and experimental tests on different road surfaces. The impact of different parameters on the vibration can be explained by this equation, which can give the engineer some instructions to design a control method to avoid this feature.
2016-04-05
Technical Paper
2016-01-1680
Suresh Abasaheb Patil, Indrajit Dinkar More
Abstract This paper incorporates the on-road real time ride comfort testing and simulation analysis of the typical passenger cars. The main objective is to analyze the vibrations to the passenger’s seat through the irregularities on road surface. This analysis is carried out with the help state-of-the-art of FFT analyzer for different classes of passenger car for variety of road conditions which have been validated by simulation analysis in the 20-Sim simulation software.
2016-04-05
Technical Paper
2016-01-1668
Hideki Fukudome
Abstract This study analyzed the longitudinal vibration of a vehicle body and unsprung mass. Calculations and tests verified that longitudinal vibration can be reduced using in-wheel motors, which generate torque very quickly. Despite increasing demand for measures to enhance ride comfort considering longitudinal vibration, this type of vibration cannot be absorbed or controlled using a conventional suspension. This paper describes the reduction of vehicle longitudinal vibration that cannot be controlled by conventional actuators.
2016-04-05
Technical Paper
2016-01-1552
Renato Galluzzi, Andrea Tonoli, Nicola Amati, Gabriele Curcuruto, Piero Conti, Giordano Greco, Andrea Nepote
Abstract The development of suspension systems has seen substantial improvements in the last years due to the use of variable dampers. Furthermore, the efficiency increase in the subsystems within the automotive chassis has led to the use of regenerative solutions, in which electric machines can be employed as generators to recover part of the energy otherwise dissipated. However, the harvesting capability of regenerative suspensions is often limited by friction and inertial phenomena. The former ones waste mechanical energy into heat, while the latter ones hamper the shock absorption by locking the suspension when subject to dynamic excitation. Besides a suitable design and sizing of components, recent research works highlight the use of the so-called motion rectifier to improve energy recovery by constraining the motion of the electric motor to a single sense of rotation.
2016-04-05
Technical Paper
2016-01-1549
Nicola Bartolini, Lorenzo Scappaticci, Francesco Castellani, Alberto Garinei
Knocking noise is a transient structural noise triggered by piston rod vibrations in the shock absorber that excite the vibration of chassis components. Piston rod vibrations can be caused by valve motion (opening and closing) and dry friction during stroke inversions. This study investigates shock absorber knocking noise in twin tube gas-filled automotive shock absorbers and its aim is to define an acceptance criterion for a sample check of the component. If, in fact, the damper comes from a large mass production, it may happen that small mounting differences lead to different behaviors that result in higher or lower levels of knocking noise. To achieve this goal, experimental tests were carried out using a hydraulic test bench; accelerometers were placed in proximity to the rebound valve and on the piston rod. The vibration phenomenon was then isolated through a post-processing analysis and a damped and unforced lumped mass model was used to characterize the vibration.
2016-04-05
Technical Paper
2016-01-1557
Francesco Castellani, Nicola Bartolini, Lorenzo Scappaticci, Davide Astolfi, Matteo Becchetti
Abstract Shock absorber is one of the most relevant sub-systems of the suspension system for a wide range of vehicles. Although a high level of development and tuning has been reached, in order to ensure high safety standards in almost every situation, some dynamic phenomena affecting vehicle handling or NHV (Noise Vibration Harshness) can appear. The aim of present work is to improve a mathematical model using experimental data from a prototype of monotube shock absorber developed for research purposes. The model takes into account all the main features affecting the global performance of the device, such as non-linear behaviour and the presence of hysteresis loops. Actually, the most important parameters are analyzed, such as flow and orifice coefficients of the valves, coefficients of mechanical compliance of the chambers and oil compressibility, dry and viscous friction coefficients.
2016-04-05
Technical Paper
2016-01-1393
Prabhakar Konikineni, V. Sundaram, Kumar Sathish, Sankarasubramanian Thirukkotti
Abstract Fan shroud is one of the critical components in an engine cooling system. It helps in achieving optimum air flow across the heat exchangers. The major challenge is to design a fan shroud which meets noise, vibration and harshness (NVH) requirements without compromising on air flow targets [1]. An improperly designed fan shroud will cause detrimental effects such as undesirable noise and vibration, which will further damage the surrounding components. In current days, multiple simulations and test iterations are carried out in order to optimize its design. The objective of this paper is to provide a design framework to achieve optimized fan shroud that meets NVH requirements in quick turnaround time using Design for Six Sigma (DFSS) approach [2]. The purpose of the Engine cooling system is to maintain the coolant temperature across the vehicle.
2016-04-05
Technical Paper
2016-01-1430
Se Jin Park, Murali Subramaniyam, Seoung Eun Kim, Tae Hyun Kim, Hee Su Sin, Dong Hag Seo, Hyu Hyeong Nam, Jeong Cheol Lee
Abstract Seating comfort is associated with the various factors, and one of the principal components of a vehicle environment which can affect passenger’s comfort is vibration. The seat design plays a vital role in the vibration isolation. In recent years, automotive seat designers are paying more attention for the improvement of seat cushion properties. This paper provides information about a new automotive seat concept that use double-wall 3D air-mat in cushion along with foam cushion in the seat cushion system. To test the developed seat on vibration isolation characteristics, seating comfort, and ride quality experiments have been performed. This research is divided into two parts. At first, the newly developed seat tested on the motion simulator. In study 2, road tests were performed on the national highway. Two tri-axial accelerometers were used to measure acceleration at the foot and hip in two different seats (seat with and without double-wall 3D air-mat).
2016-04-05
Technical Paper
2016-01-1432
Alexander Siefert
Abstract Predicting the vibration comfort is a difficult challenge in seat design. There is a broad range of requirements as the load cases strongly vary, representing different excitation levels, e.g. cobblestones or California roads. Another demand is the driver expectation, which is different for a pickup and a sports car. There are several approaches for assessing the vibrations of occupants while driving. One approach is the evaluation of comfort by integral quantities like the SEAT value, taking into account a weighting based on the human body sensitivity. Another approach is the dimension of perception developed by BMW, which is similar to psychoacoustics as the frequency range is separated with respect to occurring vibration phenomena. The seat transmissibility is in the focus of all activities. In the frequency range it defines the relation between the input at the seat slides and the output at the interface of human body and trim.
2016-04-05
Technical Paper
2016-01-1322
Tonghang Zhao, Xining Liu, Yuntao Cao, Chao Li, Hangsheng Hou
Abstract A hybrid electric vehicle (HEV) will start the engine which drives its motor to charge the battery even at idle whenever the battery power is detected to be insufficient. The activation of idle battery charging could lead to serious NVH problems if powertrain parameters are not designed or calibrated properly. This work is focused on a noise issue encountered during idle charging for a specific prototype vehicle, and investigates control strategies to contain the noise level. Based on basic principles of automobile vibration and noise control along with the specific characteristics of the hybrid vehicle architecture, this work analyzes and elucidates methods of the engine idle charging noise control from the perspectives of powertrain modal alignment, idle speed optimization, and electric motor control algorithm.
2016-04-05
Technical Paper
2016-01-1321
Masahiro Fukazawa, Tsuyoshi Murao, Shingo Unigame
Abstract The CAE method to predict the vibration transfer function of the hydraulic engine mount on a vehicle with sufficient precision and calculation time without prototype cars was developed. The transfer function is given in the following steps. First, rubber deformation form under the power train weight loaded must be predicted. It’s obtained by using a reduction model of an engine mount, as a unit, which doesn’t have its fluid sealed inside, with the technique to get the static spring characteristics in a non-linear relationship. Second, Young’s modulus and structural damping coefficient for the deformed rubber must be given. As for these characteristics, ignoring the relations between these values and strain, the constant values are used. This considerably reduces computation time and model size. Next, the reduction model and the fluid model have must be combined to express actual product. In this step, coupled analysis for fluid and structure is used.
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