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Viewing 1 to 30 of 5461
2015-10-27 ...
  • October 27, 2015 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
This seminar is designed to provide gear novices with a general understanding of gear nomenclature, geometry, and arrangements. Starting with the basic definition of gears, conjugate motion and the "Laws of Gearing", you will gain a solid understanding of gearing and the fundamentals of rotary motion transfer through gear-trains. Gear classifications, tooth forms and geometry, and very high-level application considerations, manufacturing processes, and inspection techniques will be covered. Attendees will receive a copy of the book, Gear Design Simplified, by Franklin D. Jones & Henry H. Ryffel.
2015-09-03 ...
  • September 3-4, 2015 (8:30 a.m. - 4:30 p.m.) - Shanghai, China
Training / Education Classroom Seminars
This seminar is presented in Mandarin Chinese. The course materials are bilingual (English and Chinese). Developing environmentally cleaner and more fuel efficient vehicles is transforming the automotive industry worldwide, particularly in China with its emphasis on new energy vehicles. There are many engineering challenges that must be addressed in designing effective new energy vehicles. The technical knowledge required to understand and make the right decisions with regard to powertrain architecture, powertrain controls, and energy management strategies is critical to success in this market.
2015-07-28 ...
  • July 28, 2015 (1 Session) - Live Online
Training / Education Online Web Seminars
Hybrid powertrains have been on the market for more than a decade and have become one of the most successful alternative powertrains available today. More than a million hybrids are sold globally per year, primarily in Japan and the US. Some OEMs estimate that up to 80% of their light-duty vehicles may require some level of hybridization to meet upcoming CAFE regulations in the United States. Hybrids are also starting to make inroads into markets in Europe, and have recently been introduced to Chinese and Indian markets, among others. Basic information on hybrids is scattered among information sources, and is often difficult to synthesize.
2015-06-24
Event
The focus of the Structural Analysis session is to share experiences on analyzing, testing, and developing solutions to structural noise and vibration problems from powertrain sources. Analytical modeling, experimental testing and predictive correlation are just a few of the tools used in this endeavor.
2015-06-24
Event
This session deals with analytical, computational and experimental studies of the dynamic response including noise and vibration of automotive driveline system and components. Typical topics of interests include, but not limited to, torque converters, gear noise, axle noise driveline system dynamics, transmission noise and vibrations, powertrain dynamics, transient dynamic response and propshaft balancing.
2015-06-24
Event
This session deals with analytical, computational and experimental studies of the dynamic response including noise and vibration of automotive driveline system and components. Typical topics of interests include, but not limited to, torque converters, gear noise, axle noise driveline system dynamics, transmission noise and vibrations, powertrain dynamics, transient dynamic response and propshaft balancing.
2015-06-23
Event
This session deals with analytical, computational and experimental studies of the dynamic response including noise and vibration of automotive driveline system and components. Typical topics of interests include, but not limited to, torque converters, gear noise, axle noise driveline system dynamics, transmission noise and vibrations, powertrain dynamics, transient dynamic response and propshaft balancing.
2015-06-23
Event
This session deals with analytical, computational and experimental studies of the dynamic response including noise and vibration of automotive driveline system and components. Typical topics of interests include, but not limited to, torque converters, gear noise, axle noise driveline system dynamics, transmission noise and vibrations, powertrain dynamics, transient dynamic response and propshaft balancing.
2015-06-23
Event
This session deals with analytical, computational and experimental studies of the dynamic response including noise and vibration of automotive driveline system and components. Typical topics of interests include, but not limited to, torque converters, gear noise, axle noise driveline system dynamics, transmission noise and vibrations, powertrain dynamics, transient dynamic response and propshaft balancing.
2015-06-15
Technical Paper
2015-01-2174
Yuanfeng Xia, Jian Pang, Cui Zhou, Hongcheng Li, Wenjuan Li
Study on the Bending Vibration of a Two-Piece Propeller Shaft for 4WD Driveline Yuanfeng Xia1, 2, Jian Pang1, 2,*, Cui Zhou1, 2, Hongcheng Li1, 2, Wenjuan Li1, 2 1 Changan Auto Global R&D Center, Chongqing, China, 401120 2. State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing, China, 401120 * Correspondence author, e-mail address: pangjian@changan.com.cn Currently, the four wheel drive (4WD) system is widely used in Sports Utility Vehicle (SUV) due to the increasing demand of fuel efficiency and dynamic performance by customers. However, propeller shaft consisting of different universal joints and tubes on 4WD vehicle easily induces low frequency bending vibration. This paper analyzes the characteristics of driveline bending vibration of a 4WD vehicle and provides control methods to reduce the low frequency vibration caused by propeller shaft bending resonances.
2015-06-15
Technical Paper
2015-01-2173
Srikumar C Gopalakrishnan, Teik Lim
Modeling of elastohydrodynamic lubrication phenomena for the spiral bevel gears are performed in the present study. The damping and the friction coefficient generated from the lubricated contact area will have profound effects on the dynamics of spiral bevel gears. Thus the damping value generated from this friction model will be time varying. This makes the use of constant and empirical damping value in the dynamics of spiral bevel gears questionable. The input geometric and kinematic data required for the EHL simulations are obtained using Tooth Contact Analysis. A full numerical elastohydrodynamic lubrication simulations are carried out using asymmetric integrated control volume (AICV) algorithm to compute the contact pressures. The fast Fourier transforms are used to calculate the elastic deformations on the gear surfaces due to contact load. The computed pressures and the effective viscosity are used to calculate the time varying damping for the spiral bevel gears.
2015-06-15
Technical Paper
2015-01-2176
Rajkumar Bhagate, Ajinkya Badkas, Kiran Mohan
Gear rattle is an annoying noise and vibrations phenomena of the automotive driveline, which is mainly controlled by the engine’s torque variations creating the source for torsional fluctuations. In the current work, torsional vibrations are analyzed for improving comfort of the drivetrains. A 6 DOF, 1-D multibody mathematical model for the torsional vibrations of front wheel drive automotive drivetrain is developed and utilized for the optimization of sensitive system parameters for reducing the driveline rattle. Second order differential equations of the mathematical model are solved by using MATLAB and the output response is validated with the testing data. The model is further utilized for optimizing the flywheel inertia and clutch stiffness which are considered to be most sensitive parameters for reducing the input excitations to transmission.
2015-06-15
Technical Paper
2015-01-2175
Jason Ley, Zhaohui Sun, William Braun, Jeffrey Nyquist
Vehicle driveline integration has long been recognized as a key element to vehicle NVH performance. As competition keeps rising, the consumer has also become more demanding of vehicle performance, especially in the NVH realm. However, regulations are pushing OEMs to develop lighter and more efficient vehicles; which can make traditional NVH integration solutions such as torsional or linear dampers, or propshaft tube size change both weight and cost prohibitive. In addition, the mass reduction trends at the OEM level have had the secondary consequence of creating vehicles which can be more sensitive and susceptible to modal alignment. These problems have led to an increased need for targeted, light weight, cost effective solutions that can be quickly adjusted to meet vehicle demands. This paper presents the propshaft liner development that is expanded from previously published SAE technical paper and US patents.
2015-06-15
Technical Paper
2015-01-2178
Mohamed El Morsy, Gabriela Achtenova
When localized fault occurs in a bearing, the periodic impulsive feature of the vibration signal appears in time domain, and the Corresponding bearing characteristic frequencies (BCFs) emerge in 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. The common technique of Fast Fourier Transforms (FFT) and Envelope Detection (ED) are always used to identify faults occurring at the BCFs. In the early stage of bearing failures, the BCFs contain very little energy and are often overwhelmed by noise and higher-level macro-structural vibrations. In order to extract the weak fault information submerged in strong background noise of the gearbox vibration signal, an effective signal processing method would be necessary to remove such corrupting noise and interference. Optimal Morlet Wavelet Filter and Envelope Detection (ED) are applied in this paper.
2015-06-15
Technical Paper
2015-01-2180
Almahdi Saleh, Michael Krak, Jason Dreyer
This study examines clutch damper subsystem dynamics under transient excitation and validates predictions using a new laboratory experiment (subject of a companion paper). The proposed models include multi-staged stiffness and hysteresis elements as well as spline nonlinearities. Several example cases, such as two high (or low) hysteresis clutches in series with a pre-damper, are considered. First, detailed multi-degree of freedom nonlinear models are constructed, and their time domain predictions are validated by analogous measurements. Second, key damping sources that affect transient events are identified, and appropriate models or parameters are selected or justified. Finally, torque impulses are evaluated using metrics, their effects on driveline dynamics are quantified, and dynamic interactions between clutch damper and spline backlash nonlinearities are briefly discussed.
2015-06-15
Technical Paper
2015-01-2179
Laihang Li, Rajendra Singh
The transient vibration phenomenon in a vehicle powertrain system during the start-up (or shut-down) process is studied with focus on the properties of multi-staged clutch damper. First, a four-degree-of-freedom torsional model with multiple discontinuous nonlinearities, under flywheel motion input, is developed, and the transient event is validated with a vehicle start-up experiment. Second, the role of the nonlinear clutch damper on the transient event is investigated in time and time-frequency domains; interactions between the clutch damper and the transmission transients are estimated. Third, a semi-analytical method is applied to a simplified and validated single-degree-of-freedom powertrain system model to examine the nonlinear characteristics of clutch damper during a slowly varying non-stationary process. Finally, analytical formulas are successfully verified to approximate the nonlinear amplification level for a rapidly varying process.
2015-06-15
Technical Paper
2015-01-2182
Yawen Wang, Junyi Yang, Teik Lim
Due to the design of lightweight, high speed driveline system, the large displacement of shaft rotation and rotor dynamics must be considered to predict vibratory responses more realistically. In the current analysis, a lumped parameter model of the propeller shaft is developed with Timoshenko beam elements, which includes the effect of rotary inertia and shear deformation. The propeller shaft model is then coupled with a hypoid gear pair representation using the component mode synthesis approach. In the proposed formulation, the gyroscopic effect of both the gear and propeller shaft is considered. The simulation results show that the interaction between gear gyroscopic effect and propeller shaft bending flexibility has considerable influence on the gear dynamic mesh responses around bending resonances, whereas the torsional modes still dominate in the overall frequency spectrum.
2015-06-15
Technical Paper
2015-01-2181
Dong Guo, Yawen Wang, Teik Lim, Peng Yi
A combined lumped parameter, finite element (FE) and boundary element (BE) model is developed to predict the whine noise from rear axle. The hypoid geared rotor system, including the gear pair, shafts, bearings, engine and load, is represented by a lumped parameter model, in which the dynamic coupling between the engaging gear pair is represented by a gear mesh model condensed from the loaded tooth contact analysis results. The lumped parameter model gives the dynamic bearing forces, and the noise radiated by the gearbox housing vibration due to the dynamic bearing force excitations is calculated using a coupled FE-BE approach. Based on the predicted noise, a new procedure is proposed to tune basic rear axle design parameters for better sound quality purpose. To illustrate the salient features of the proposed method, the whine noise from an example rear axle is predicted and tuned.
2015-06-15
Technical Paper
2015-01-2184
Syeda Mahmud, Shahjada Pahlovy
Fuel efficiency can be improved by reducing the energy loss of power train and it’s components. Some estimates shows that about 14%–30% of the energy from the fuel gets used to move a car down the road and 5-6% energy is lost due to drive train. Therefore, a potential improvement of power train components can lower the fuel consumption significantly. Due to the engagement and disengagement process of transmission clutches, a frictional heat is generated which leads to some damage to clutches. Therefore, it is necessary to cool down the disks to increase the service life of clutch. An automatic transmission fluid (ATF) is delivered in between the friction disks and separator plate to cool them. Since the friction plates and separator plates are always in relative motion to each other, a shear force is generated on the fluid in the gap between the disks. This shear force generates a drag torque which is considered as a loss.
2015-06-15
Technical Paper
2015-01-2183
Thomas Wellmann, Kiran Govindswamy, Jeff Orzechowski, Sudharsan Srinivasan
Integration of automatic engine start/stop systems in “conventional” drivetrains with 12V starters is a relatively cost effective measure to reduce fuel consumption. Therefore, automatic engine start/stop systems are becoming more prevalent and increasing market share of such systems is predicted. A quick, reliable and consistent engine start behavior is essential for customer ac-ceptance of these systems. The launch of the vehicle should not be compromised by the start/stop system, which implies that the engine start time and transmission readiness for transmitting torque should occur within the time the customer releases the brake pedal and de-presses the accelerator pedal. Comfort and NVH aspects will continue to play an important role for customer acceptance of these systems. Hence, the engine stop and re-start behavior should be imperceptible to the driver from both a tactile and acoustic standpoint.
2015-06-15
Technical Paper
2015-01-2186
Sudharsan Srinivasan, Jeff Orzechowski, Michael Schoenherr
Every automaker is looking for ways to improve the fuel economy of its vehicle fleet to meet the EPA regulation for 2025 Corporate Averaged Fuel Economy of 54.5 mpg. Engine Stop Start technology will improve the fuel economy of the vehicle by shutting down the engine when the vehicle is stationary. While this is an established technology in Europe, it is gaining momentum in North America where NVH refinement is a stronger consideration. Stop Start technology needs to be seamlessly incorporated into the vehicle. This paper gives an overview of characterizing an auto start based on the features of a few Powertrain-system-level metrics. Following the fundamentals of NVH, (Source, Path and Receiver) the receiver touch points will be less perceptible to vibration, if the powertrain-system source is made smoother. Tangential components, which are functions of cylinder pressure and crank angle, are the dominant forces during auto start.
2015-06-15
Technical Paper
2015-01-2188
Zhaohui Sun, Glen Steyer, Chih Hung Chung
With the high competitiveness in the automotive industry and the pressure of CAFE regulation, the trend of using lightweight and mass optimized structures becomes one of the key factors for future success of an auto company. Utilizing alternative metals such as aluminum to replace traditional cast iron or steel have become more common. Aluminum carrier drive axles pose new challenges to engineers, particularly for product NVH performance. This is largely due to the significantly higher thermal expansion rate and lower elastic modulus of aluminum compared with cast iron and steel. This paper discusses approaches to properly design aluminum axles for optimized NVH characteristics. By effectively using well established and validated FEA and other CAE tools, key factors that are particularly associated with aluminum axles are analyzed and discussed.
2015-06-15
Technical Paper
2015-01-2192
Manchi Venkateswara Rao, Jos Frank, Prasath Raghavendran
Meeting various customer(s) requirements with the given automotive product portfolio within the stipulated time period is a challenge. Design of product configuration matrix is an intelligent task and it requires information about vehicle performance for different configurations which helps in deciding the level of new development. Most often the situation arises, particularly in the field of NVH, to strike the right balance between engine power and structural parameters of the body. The sensitivity of engine power on the overall NVH behavior is the key information necessary to take major business decisions. In this paper, the effect of change in torsional fluctuation of the engine on the NVH behavior of the rear wheel drive vehicle is experimentally studied. The torsional fluctuation of the driveline are given as input with the help of electric motor to the existing test vehicle at its differential end and the current NVH levels are measured.
2015-06-15
Technical Paper
2015-01-2191
Peng Yu, Tong Zhang, Shiyang Chen, Jing Li, Rong Guo
In view of the problem of low-frequency longitudinal vibration exists in a pure electric vehicle, modeling methods of driveline torsion vibration system are conducted. Firstly, dynamometer test is performed, signals of motor speed and seat rail acceleration are obtained, the frequency characteristics of flutter is determined using the order analysis and time frequency analysis. Then four types of modeling and analysis are investigated facing the driveline torsion vibration problem, including single model without electromagnetic stiffness, branch model without electromagnetic stiffness, single model considering electromagnetic stiffness and branch model considering electromagnetic stiffness. The results show that, modeling taking into account the electromagnetic stiffness and branches can reflect more low-frequency characteristics, helps to reveal the low-frequency longitudinal flutter of electric vehicle.
2015-06-15
Technical Paper
2015-01-2190
Manchi Venkateswara Rao
Mount development and optimization plays a significant role in vehicle NVH refinement as they significantly influence overall driving experience. Dynamic stiffness is a key parameter that directly affects the mount performance. Conventional dynamic stiffness evaluation techniques are cumbersome and time consuming. The dynamic stiffness of mount depends on the load, frequency of application and the displacement. The above parameters would be far different in the test conditions under which the mounts are normally tested when compared to operating conditions. Hence there is need to find the dynamic stiffness of mounts in actual vehicle operating conditions. In this paper, the dynamic stiffness of elastomeric mounts is estimated by using a modified matrix inversion technique popularly termed as operational path analysis with exogenous inputs (OPAX).
2015-06-15
Technical Paper
2015-01-2228
Drivelines used in modern pickup trucks commonly employ universal joints. This type of joint is responsible for second driveshaft order vibrations in the vehicle. Large displacements of the joint connecting the driveline and the rear axle have a detrimental effect on vehicle NVH. As leaf springs are critical energy absorbing elements that connect to the powertrain, they are used to restrain large axle windup angles. One of the most common types of leaf springs in use today is the multi-stage parabolic leaf spring. A simple SAE 3-link approximation is adequate for preliminary studies but it has been found to be inadequate to study axle windup. A vast body of literature exists on modeling leaf springs using nonlinear FEA and multibody simulations. However, these methods require significant amount of component level detail and measured data. As such, these techniques are not applicable for quick sensitivity studies at design conception stage.
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