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2015-06-09
Article
For the design process of the class of aircraft known as an efficient supersonic air vehicle, particular attention must be paid to the propulsion system design as a whole, including installation effects integrated into a vehicle performance model.
2015-05-14
Article
The newly named Johnson Controls Vehicle Engineering Laboratory, on the Lawrence Technological University campus in Michigan, will serve the energy-storage-system supplier and benefit LTU engineering students.
2015-05-13
Technical Paper
2015-36-0004
Patric Daniel Neis, Ney Francisco Ferreira, Luciano Tedesco Matoso, Diego Masotti, Jean Carlos Poletto
Abstract The present paper addresses an investigation about the definition of a parameter for quantifying the creep-groan propensity in brake pads. Creep-groan is a self-excited vibration caused by stick-slip phenomenon [1, 2, 3]. For the definition of the creep-groan propensity parameter, extensive experimental work was performed on a laboratory-scale tribometer. The experiments are divided in two main parts: (i) study of correlation between accelerometer signal with physical and operating parameters. (ii) validation of the chosen parameter, which was based on stick-slip tests performed with three different materials, one low-metallic (low-met) and two non-asbestos organic (NAO 1 and 2). From the first study, it was found that both the slip power and mean torque multiplied by torque variation showed a slightly higher correlation with the acceleration signal.
2015-05-13
Technical Paper
2015-36-0002
Keshav Sundaresh, Felipe Moretti Leila
Abstract The level of noise transmitted to the passengers of a vehicle can drastically impact a passenger's comfort. Brake noise will give the customer an impression of poor product quality and can thus damage the quality image of the company. Within the automotive industry, the study of mode coupling instability by the use of FEM and modal complex analysis is widespread to reduce this phenomenon. In this paper an alternative method is presented, where potential brake noise issues are predicted by the use of a time transient integration using multi-body system analysis. The simulation model contains a nonlinear contact description, bushing, flexible bodies and the axis kinematics of the vehicle. Transient results are transformed by Fourier for a frequency domain study. The parameters that can be varied for the prediction analysis are brake pressure, vehicle speed, friction laws, system damping and bushing properties.
2015-05-13
Technical Paper
2015-36-0026
André G. L. Suetti, Robson Pederiva
Abstract In the field of engineering, there is a well known phenomenon called “stick-slip” a specific type of vibration in a mechanical system where friction is involved, it is qualified as non-linear, auto-excited and generally stable within a limited cycle. During stick-slip, the behavior of the friction coefficient as a function of the sliding velocity has big influence on the wave pattern, wherein various models can be found in the literature. Besides affecting wave patterns, this behavior affects significantly the amount of damping necessary to reach an asymptotic level of stability. The objective of this work is to study various friction models found in literature, for example: constant transition between coefficients, linear and exponential and apply these models in mechanical systems that represent brake systems.
2015-05-05
Article
At Intermat, LiuGong announced that it was in a 60-day countdown before its new Global Research and Development Center opens in June at Liuzhou, also home to the company's global headquarters.
2015-05-01
Journal Article
2015-01-9106
Magnus Löfdahl, Arne Nykänen, Roger Johnsson
Abstract In the automotive industry, tire noise is an important factor for the perceived quality of a product. A useful method to address such NVH problems is to combine recordings with measurements and/or simulations into auralizations. An example of a method to create structure-borne tire noise auralizations is to filter recordings of hub forces and moments through binaural transfer functions experimentally measured from the hub of the car to an artificial head in the car cabin. To create authentic auralizations of structure-borne sound, all six degrees of freedom (DOFs) of hub forces and moments and transfer functions should be included. However, rotational DOFs are often omitted due to measurement difficulty, complexity, time, and cost. The objective was to find which DOF (or DOFs) is perceived as most prominent in structure-borne tire noise. An auralization model of interior structure-borne tire noise was used.
2015-04-30
Article
New AWD systems from BorgWarner and Honda deliver significant improvements in efficiency, as well as vehicle dynamic performance.
2015-04-30
Standard
J1174_201504
This SAE Recommended Practice establishes the instrumentation and procedure to be used in measuring the operator ear sound level for engine powered equipment under 30 kW (40 bhp). The sound levels obtained by using this procedure are representative of the sound levels generated by the equipment under typical operating conditions. It is intended to include equipment such as lawn mowers, snow blowers, and tillers. It is not intended to include equipment designed primarily for operation on highways or within factories or buildings, or vehicles such as motorcycles, snowmobiles, and pleasure motorboats that are covered by other SAE Standards or Recommended Practices. This procedure does not cover handheld equipment such as chainsaws, leaf blowers, and trimmers. This SAE Recommended Practice may also be used when measuring the operator ear sound level of similar equipment powered by electricity or other power sources.
2015-04-30
Standard
J2883_201504
This SAE Recommended Practice describes a laboratory test procedure for measuring the random incidence sound absorption performance of a material or a part in a small size reverberation room by measuring decay rates. The absorption performance may include sound absorption coefficient of the test sample and or the amount of energy absorbed by the test sample. Materials for absorption treatments may include homogeneous materials, nonhomogeneous materials, or a combination of homogeneous, nonhomogeneous, and/or inelastic impervious materials. These materials are commonly installed in the mobility products and in the transportation systems such as ground vehicles, marine products, aircraft, and commercial industry (in industrial and consumer products) to reduce reverberant sound build-up and thus reduce the noise level in the environment by minimizing reflections off of hard surfaces.
2015-04-29
Article
One of the key differentiators of the EP-8100 for commercial and military simulation and training is the system’s ability to use customers’ existing databases.
2015-04-28
Article
EM Test now offers the VDS 200Q Series, a four-quadrant voltage drop simulator that can source and sink current using a programmed voltage in both positive and negative polarities.
2015-04-24
Article
Julabo introduces two additional highly dynamic temperature control systems: the process circulators Presto A45 and A45t.
2015-04-24
Article
Boeing is in the midst of several months of flights with its ecoDemonstrator 757 in a first-round effort to evaluate new technologies in 2015 that are expected to reduce environmental effects on natural laminar flow as a way to improve aerodynamic efficiency while reducing noise and carbon emissions.
2015-04-24
Article
The engine bay is an essential component of the AgustaWestland AW609 tilt rotor nacelle, since it determines the performance of the engine and assures safe maneuvers for every flight condition.
2015-04-21
Article
Schmitt Industries announces availability of the AR 2000 line, with special capabilities for distance measurement on hot surfaces—e.g., red hot, glowing steel, and for outdoor use in bright lighting conditions with high constant or stray light levels.
2015-04-15
Article
Given the pace of innovation, the goal of autonomy and automation will force more and more features into the electronics of off-highway vehicles, according to Ian Fountain, NI's Director of Application Segments.
2015-04-15
Standard
J2455_201504
The product for which data is to be available is for class 6 and larger, i.e., gross vehicle weight ≻ 9.6 kg (19500 lb). The objective is to establish a set of data requirements which powertrain component suppliers would have readily available to facilitate drivetrain system vibration compatibility and control studies.
2015-04-14
Collection
This technical paper collection sets out to reflect the recent advances on the research, development and practices of Powertrain NVH treatment. The technical papers are of interest to powertrain system designers, testing specialists, NVH experts, and other individuals who evaluate and develop technologies to control powertrain NVH. The coverage includes: engine, engine subsystem and components noise and vibration; powertrain systems noise measurement and instrumentation; powertrain systems noise analysis.
2015-04-14
Technical Paper
2015-01-1555
Charalampos Kounenis, David Sims-Williams, Robert Dominy, Arganthaël Berson, Nicholas Oettle, Claire Freeman
Abstract A vehicle driving on the road experiences unsteady flow conditions which are not generally reproduced in the development environment. This paper investigates the potential importance of this difference to aeroacoustics and hence to occupant perception and proposes a methodology to enable better ranking of designs by taking account of wind noise modulation. Two approaches of reproducing the effects of unsteady wind on aeroacoustics were investigated: an active wind tunnel Turbulence Generation System (TGS) and a quasi-steady approach based on measurements at a series of fixed yaw angles. A number of tools were used to investigate the onset flow and its impacts, including roof-mounted probe, acoustic heads and surface microphones. External noise measurements help to reveal the response of separate exterior noise sources to yaw.
2015-04-14
Technical Paper
2015-01-0235
Shiv Shankar Prasad, Jahangir Mansoori, Jin Seo Park
Abstract A vehicle horn is a sound-making device used to warn others of any approaching vehicle or of its presence. Some countries require horns by law. Conventional Horns are electromechanical with steel diaphragm and electromagnet acting upon it. Switching of horn is performed by mechanical contact breaker assembly that repeatedly interrupts the current to electromagnetic. Up-Down movement of diaphragm with response to the current creates a sound wave across horn. Conventional Horn faces the problem of wear and tear of mechanical contact and internal parts. Switching of contacts results in arcing. There is no current and surge voltage protection for the coil of conventional horn. These problems of conventional system might be accepted in the general market, but in specific markets which are using horn frequently; these have to be considered as serious issues. Especially, horns are one of the most abusive parts of vehicle in India.
2015-04-14
Technical Paper
2015-01-0430
Frédéric Kihm, Andrew Halfpenny, Benoît Beaum
Abstract As part of the design and validation of engine-mounted components, it is essential to define the vibratory mechanical environment in which these components will operate. This is required in order to optimize the reliability of such components subjected to loading from both the engine and road profile, while minimizing development costs and time scales. This paper presents a methodology that superimposes a swept sine on a power spectral density of acceleration in order to evaluate the mechanical durability of engine mounted or gear box mounted components. The first step in the process is to obtain the wave form of the dominant engine orders by extracting the deterministic signals from the random process using an order tracking method in the time domain. The second step is to assess the fatigue damage and extreme response spectra of a Swept-Sine-On-Random profile.
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.
2015-04-14
Technical Paper
2015-01-1087
Juergen Greiner, Martin Grumbach, Albert Dick, Christoph Sasse
Abstract Market trends clearly demonstrate the ongoing worldwide acceptance and success of modern automatic transmission solutions (AT, CVT, DCT) in both passenger cars and light trucks. This success is based on the further development of the driving comfort, shifting dynamics and - most important - the fuel consumption reduction modern automatic transmission systems offer. First, key driveline parameters such as overall spread and number of ratio's are to be discussed. The optimum spread for the fuel efficiency is in the range of about 8 to 9 and can typically be achieved by 8 to 10-speed transmissions. This is because modern gasoline or diesel-engines have a rather flat characteristic fuel map. Therefore the inner efficiency of the future transmissions becomes increasingly important.
2015-04-14
Technical Paper
2015-01-0663
Ling Zheng, Zhanpeng Fang, Zhongcai Tang, Zhenfei Zhan, Jiang-hua Fu
Abstract The design optimization of vehicle body structure is addressed to reduce interior noise and improve customer satisfaction in this paper. The structural-acoustic model is developed by using finite element method. The frequency response of structural-acoustic system is computed by modal analysis method. The optimization problem is constructed to minimize the sound pressure level in the right ear of the driver. The sensitivity analysis is carried out to find the key panels to be optimized as design variables and improve the efficiency of optimization computation. Response Surface Method (RSM) is utilized to develop the surrogate model and optimize the vehicle Noise Vehicle and Harshness (NVH) behavior. A 9dB reduction of sound pressure level (SPL) in the right era of the driver is obtained through geometric optimization for panels. Furthermore, the topology optimization model is developed to search the optimal layout of constrained layer damping treatments in the front floor.
2015-04-14
Technical Paper
2015-01-0672
Douglas Marriott, Takeshi Ohtomo, Tohru Wako
Abstract Predicting sloshing noise as early as possible during the design process has become an increasingly desired simulation for fuel tank suppliers as the demand for quieter vehicles increase. Simulating early on in the design process enables suppliers to build products directly to customer specifications, at a lower cost and shorter timeframe. The procedure to accurately and efficiently analyze complete sloshing noise behavior has to date not been fully established. Current methods rely on indirect noise deduction based on specific positions from Fluid-Structure Interaction (FSI) analyses or uncoupled fluid analysis with separate structural and acoustic analyses. In this paper, we introduce a technique to analyze the fully coupled sloshing noise generated in the fuel tank of an automobile. The technique takes advantage of combining an explicit coupled Lagrangian and Eulerian solver with an acoustics solver.
2015-04-14
Technical Paper
2015-01-0617
Jie Zhang, Xiao Chen, Bangji Zhang, Lifu Wang, Shengzhao Chen, Nong Zhang
Abstract This paper demonstrates time response analysis of the mining vehicle with bounce and pitch plane hydraulically interconnected suspension (HIS) system. Since the mining vehicles working in harsh conditions inducing obvious pitch motion and the hard stiffness of suspensions leading to the acute vibration, the passive hydraulically interconnected system is proposed to provide better ride comfort. Furthermore, the hydraulic system also increases the suspension stiffness in the pitch mode to prevent vehicle from large pitch motions. According to the hydraulic and mechanical coupled characteristic of the mining vehicles, a 7degrees of freedom (7-DOFS) mathematical model is employed and the state space method is used to establish the mechanical and hydraulic coupled dynamic equations. In this paper, the vehicles are subjected to straight line braking input, triangle block bump input applied to the wheels and random road tests.
2015-04-14
Technical Paper
2015-01-0618
Zhihong Dong, Ying Sun, Guitao Zhu, Shihu Wang, Jian Zeng, Yuliang Yang
Abstract Based on the modal frequency response theory and experiment, the installation layout evaluation and structural optimization method for SIS(side impact sensors) installation position is studied. Establish the finite element model including B-pillar, roof and floor with local constraint. Than study the key parameter's influence on the frequency response analysis results, and the simulation results are correlated by experiment. In view of the installation layout requirements of side impact sensors, the structure optimization method for installation position of side impact sensor is put forward. The optimal scheme is confirmed by the finite element analysis, and a final experimental verification was implemented by a real vehicle test.
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
Technical Paper
2015-01-0613
Donghong Ning, James Coyte, Hai Huang, Haiping Du, Weihua Li
Abstract This paper presents a study on experimental vibration simulation using a multiple-DOF motion platform for heavy duty vehicle seat suspension test. The platform is designed to have 6-DOF with the advantages of high force-to-weight ratio, high dexterity and high position accuracy. It can simulate vehicle vibrations in the x, y and z translational axis and in the roll pitch and yaw axis rotation. To use this platform to emulate the real vibration measured from vehicle seat base under real operation for vehicle seat suspension test in lab, an Inertial Measurement Unit (IMU) is applied to collect the acceleration data from a real vehicle. An estimation algorithm is developed to estimate the displacement from the measured acceleration. The estimated displacement is then used to calculate the length of each leg of the platform so that the platform can generate the motion similar to the measured one.
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