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2017-12-04 ...
  • December 4-15, 2017 (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.
2017-11-28 ...
  • November 28-December 1, 2017 (3 Sessions) - Live Online
Training / Education Online Web Seminars
This web seminar will provide an introduction to the characteristics of sound waves, human perception of sound, sound and vibration measurements, measurement facilities, and various noise sources and noise control principles. It will include an overview of sound pressure, power, intensity, decibels, and frequencies. Practical examples will be used to familiarize participants with the acoustic fundamentals for solving noise and vibration problems and the associated solution principles.
2017-11-06 ...
  • November 6, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
The influx of different hybrid and electric vehicle configurations has brought about unique NVH challenges from a variety of sources. NVH refinement is an important aspect of powertrain development and the vehicle integration process. While developing the NVH behavior of the vehicle is critical to satisfy customer expectations, it is also important to consider the influence of reduced exterior noise levels on pedestrian safety.
2017-10-08
Technical Paper
2017-01-2428
Peilin Dai, Ying Huang, Donghao Hao, Ting Zhang
Abstract: The vehicle driveline suffers low frequency torsional vibration because of the abrupt change of torque and torque fluctuation of variable frequency. This problem can be solved by model-based predictive control, so building a control oriented driveline model is extremely important. The traditional off-line identified model which does not consider driveline parameter variation such as damping of tire and suspension during vehicle operation cannot accurately reflect the true characteristics of the driveline vibrations. And usually the fixed stiffness is considered, this will cause modeling errors and worse result of vibration control, in this paper, an on-line recursive identification method is proposed and verified based on an electric car. First of all, as for the low frequency vibration, the control oriented model is simplified into a six-parameter model with double inertia.
2017-10-08
Technical Paper
2017-01-2333
Marcos Gutierrez, Andres Castillo, Juan Iniguez, Gorky Reyes
The aim for cleaner and more efficient energy from the internal combustion engines makes necessary to ensure the conditions for the exploitation of alternative fuels. The vibrations on engines are primarily understood as effects of mechanical failures, but the engine vibration is subject of the fuel combustion effects too. This effects will depend on the fuel type and its capacity to be burned. The vibrations of a diesel engine were measured and analyzed with a frequency spectrum calculated with Fast Fourier Transforms. The engine was operated with a fuel blend from 10 % recycled lubricating oil with 90% diesel as well as only diesel. It was found the engine operation with this fuel blend has a lower vibration level in comparison with the use of pure diesel. The goal of this research is to determine the properties of the fuel blend, which provides more stability to the engine by means of vibrations reduction.
2017-10-08
Technical Paper
2017-01-2283
Anand Prabu Kalaivanan, Gnanasekaran Sakthivel
Electronic Fuel Injection Systems have revolutionised Fuel Delivery and Ignition timing in the past two decades and have reduced the Fuel Consumption and Exhaust Emissions, ultimately enhancing the Economy and Ecological awareness of the engines. But the ignition/injection timing that commands the combustion is mapped to a fixed predefined table which is best suited during the stock test conditions. However continuous real time adjustments by monitoring the combustion characteristics prove to be highly efficient and be immune to varying fuel quality, lack of transient performance and wear related compression losses. Addressing Fuel Quality Issues: For developing countries, Automobile Manufacturers have been Tuning the Ignition/Injection timing Map assuming the worst possible fuel quality. Conventional knock control system focus on engine protection only and doesn't contribute much in improving thermal efficiency.
2017-10-08
Technical Paper
2017-01-2426
Zhiming Zhang, Weimin Wang, Jiangtao Wang, Jiming Zhang, Yuanda Chen, Wenlong Zhang, Guofang Yang, Fugui Fan, Wenxiang Zhang, Fengqin Huang, Xiangwang Li
Turbo-charged GDI technology is more and more widely used, which can meet the high demand of the engine performance and efficiency, but the resulting reliability and NVH issues also need to be paid attention to. Traditional NVH performance is mostly based on the experience design, repeatable test, which leads to longer development period, high cost, and also ineffective results. Along with the development of the simulation technology, NVH performance simulations play more important role in engine vibration and noise prediction. Usually The Force response analysis is used to compare the NVH performance of the engine structure, considering the standard excitation. Currently, dynamic analysis of the crank train, valve train, and piston can be carried out, and then the whole engine vibration and airborne noise can be predicted directly, considering different speed and load. In this paper, The NVH performance of a turbo-charged GDI engine is studied based on the simulation and experiment.
2017-10-02 ...
  • October 2-6, 2017 (8:00 a.m. - 8:00 p.m.) - Troy, Michigan
Training / Education Classroom Engineering Academies
This Engineering Academy covers a variety of vehicle noise control engineering principles and practices. Two specialty tracks are available: Vehicle Interior Noise and Powertrain Noise. While the Vehicle Interior Noise track focuses on the understanding and application of acoustical materials to optimize NVH in the passenger or operator compartment of a vehicle, the Powertrain Noise track focuses on NVH issues generated by powertrain noise sources and the design strategies to minimize them. Noise sources include engines, transmissions/transfer cases, accessories, exhaust, gears, axles, joints, and couplings.
2017-10-02 ...
  • October 2-6, 2017 (8:00 a.m. - 8:00 p.m.) - Troy, Michigan
Training / Education Classroom Engineering Academies
This Engineering Academy covers a variety of vehicle noise control engineering principles and practices. Two specialty tracks are available: Vehicle Interior Noise and Powertrain Noise. While the Powertrain Noise track focuses on NVH issues generated by powertrain noise sources and the design strategies to minimize them, the Vehicle Interior Noise track focuses on the understanding and application of acoustical materials to optimize NVH in the passenger or operator compartment of a vehicle. Considerable attention is given to current measurement and instrumentation technologies and their effective use.
2017-09-22 ...
  • September 22, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Brake noise is one of the highest ranked complaints of car owners. Grunts, groans, squeaks, and squeals are common descriptions of the annoying problem which brake engineers spend many hours trying to resolve. Consumer expectations and the high cost of warranty repairs are pushing the optimization of brake NVH performance. This course will provide you with an overview of the various damping mechanisms and tools for analyzing and reducing brake noise. A significant component of this course is the inclusion of case studies which will demonstrate how brake noise squeal issues have been successfully resolved.
2017-09-21 ...
  • September 21, 2017 (8:30 a.m. - 4:30 p.m.) - Troy, Michigan
Training / Education Classroom Seminars
Brake Noise, Vibration, and Harshness (NVH) is recognized as one of the major problems currently faced by the automotive manufacturers and their suppliers, with customers warranty claims of more than $100 million per year for each manufacturer. With increasing consumer braking performance expectations, automotive OEM’s and suppliers need the ability to predict potential problems and identify solutions during the design phase before millions of dollars have been spent in design, prototyping, and manufacturing tooling.
2017-09-19
Technical Paper
2017-01-2137
Dnyaneshwar V. Kadam, Sangram D. Jadhav
Vibration is the most considerable factor in dynamics of machinery. Vibration causes unfavorable effects on engine components and may reduce the life of engine. The conventional fossil fuel sources are limited in the world. The dependency on diesel should be reduced by using biodiesel as an alternative fuel in next few years. The input parameters are affected on engine performance and emission. The present study mainly focuses on an optimization of vibrations, performance and emission using Taguchi and multiple regression analysis for biodiesel as a fuel. The test was performed on single cylinder, four-stroke, diesel engine with VCR. Taguchi method is used to prepare the design of experiment of L16 array for minimizing number of experiments and multiple regression analysis for finding the best relationship between the input and output parameters. The selected input parameters are: fuel fraction, compression ratio, injection pressure and injection timing.
2017-09-17
Technical Paper
2017-01-2488
Manuel Pürscher, Peter Fischer
Vehicle road tests are meaningful for investigations of creep groan noise. However, problems in reproducing experiments and partly subjective evaluations may lead to imprecise conclusions. This work proposes an experimental test and evaluation procedure which provides a precise and objective assessment of creep groan. It is based on systematic corner test rig experiments and an innovative characterization method. The exemplary setup under investigation consisted of a complete front wheel suspension and brake system including all relevant components. The wheel has been driven by the test rig’s drum against a brake torque. The main parameters within a test matrix were brake pressure and drum velocity. Both have been varied stepwise to scan the relevant operating range of the automobile corner system for potential creep groan noise. Additionally, the experiments were extended to high brake pressures, where creep groan cannot be observed under road test conditions.
2017-09-17
Technical Paper
2017-01-2485
Tarun Teja Mallareddy, Peter Blaschke, Sarah Schneider, Daniel J. Alarcón
Brake squeal is an NVH issue experienced by brake systems and vehicle manufacturers for decades. This leads to customer dissatisfaction and the questioning of quality of the brake system. Advanced testing tools, design modification, dynamometer testing, vehicle validation etc., are performed to study, analyze and eliminate this problem. But, still it continues to exist. One of the most important reasons is the complexity of the brake pad which leads to its non-linear properties. Therefore, it is imperative to understand the behavior of the brake pad, in terms of its dynamic properties (eigenfrequencies, damping and mode shapes), under varying boundary conditions. Experimental Modal Analysis (EMA) is used to study the dynamic properties of any structure and is generally performed under free-free boundary conditions. An approach to study brake pads under pressure condition is a step towards reality, as brake pads squeal only during braking events.
2017-09-17
Technical Paper
2017-01-2489
Christian Ball, Li Lee, Weicherng Wang
The standard method for using FEA to predict and eliminate brake squeal has been to use complex eigenvalue analysis (CEA). Energy flow analysis has been adapted for use with FEA for brake squeal as an alternate mechanism for squeal prediction. This paper demonstrates an implementation of energy flow analysis with commercially available FEA software. The approach leverages the ability of the Abaqus FEA solver to obtain a quasi-static, pre-loaded brake model, as well as Abaqus’ eigenvalue extraction algorithms to create a modal space for energy flow calculations. This modal space, as well as the pre-loaded stiffness matrix, is then utilized to calculate energy flow values between nearby system modes. Three case studies are presented that compare the results of CEA and energy flow to different systems and countermeasures adopted to reduce noise occurrence in physical testing.
2017-09-17
Technical Paper
2017-01-2494
Severin Huemer-Kals, Manuel Pürscher, Peter Fischer
Complex Eigenvalue Analysis (CEA) is widely established as a mid- to high-frequency squeal simulation tool for automobile brake development. As low-frequency phenomena like creep groan or moan become increasingly important and appropriate time-domain methods are presently immature and expensive, some related questions arise: Is it reasonable to apply a CEA method for low-frequency brake vibrations? Which conditions in general have to be fulfilled to evaluate a disk brake system’s noise, vibration and harshness (NVH) behavior by the use of CEA simulation methods? Therefore, a breakdown of the mathematical CEA basis is performed and its linear, quasi-static approach is analyzed. The mode coupling type of instability, a common explanation model for squeal, is compared with the expected real world behavior of creep groan and moan phenomena.
2017-09-17
Technical Paper
2017-01-2484
Yoshiyuki Yamaguchi, Tsuyoshi Kondo
We considered the relation between disc brake’s in-plane mode noise and exciting energy which flows into pad surface for improving brake noise performance. The exciting energy is calculated by the pad’s displacement of disc rotating direction and pad thickness direction which is acquired by 3D scanning laser Doppler measurement system.
2017-09-17
Technical Paper
2017-01-2487
Yasuyuki Kanehira, Yusuke Aoki, Yukio Nishizawa
Brake squeal is uncomfortable noise that occurs while braking. It is an important issue for automobile quality to prevent brake products from squealing. Brake shims are widely used to reduce squeal occurrence rate. In particular, laminated shims can effectively suppress squeal via the viscoelastic damping of an adhesive layer. However, there are cases where the damping performance at low temperature and the durability performance at high temperature deteriorate. In that regard, we thought of applying frictional damping to shims instead of relying on a temperature-sensitive adhesive layer. To study the application of frictional damping as a new damping mechanism for shims, it is necessary to clarify the characteristics thereof. In order to quantify the damping performance of shims, loss factor has been generally measured with a bending mode tester. However, the influence of friction cannot be evaluated because it is measured under pressure-free condition.
2017-09-17
Technical Paper
2017-01-2528
Seongjoo Lee, JeSung Jeon, JooSeong Jeong, Byeongkyu Park, ShinWook Kim, ShinWan Kim, Seong Kwan Rhee, Wan Gyu Lee, Young sun Cho
It is widely believed or speculated that higher pad compressibility leads to reduced brake squeal and that caliper design can affect brake squeal. After encountering anecdotalcontradictory cases, this investigation was undertaken to systematically generate basic data and clarify the beliefs or speculations. In order to adjust pad compressibility, it is common to modify molding temperatures, pressures and times, which in addition to changing the compressibility, changes the coefficient of friction at the same time. In order to separate these two effects, NAO disc pads were prepared under the same molding conditions while using different thicknesses for the underlayer to achieve different compressibilities, thus changing compressibility without changing thecoefficient of friction. Test results show brake squeal increasing with increasing compressibility, contrary to the common belief.
2017-09-17
Technical Paper
2017-01-2530
Georg Peter Ostermeyer, Johannes Otto, Seong Kwan Rhee
The dynamics and, in particular, the NVH phenomena in brakes are still in the focus of research. Recent investigations of, for example, Rhee et al show two principal vibrational forms of the linings on the rotor. The first form is characterized by vibrations, where both linings are in phase. This produces in plane vibrations of the rotor and results in high-frequency squeeling events in the brake. The second form is an antiphase vibration of the brake linings with respect to each other. This produce directly out of plane vibrational modes of the disc. This results in lower-frequency caliper and rotor oscillations. One hypothesis is that different wear densities of the linings essentially characterize the two vibrational modes. This paper deals with a low dimensional dynamical system and examines the vibrations, the associated wear characteristics, and analyzes essential influencing parameters on the different vibrational events.
2017-09-17
Technical Paper
2017-01-2486
Kyung Jae Lee, Dong Won Kim, Daekyung Ko
Brake grinding noise is caused by the friction of the disc and pads. The friction generates vibration and it transmits to the body via the chassis system. We calle it structure-borne noise. To improve the noise in the vehicle development, the aspects of chassis or body's countermeasure occurs many problems, cost and time. In this reason many brake company try to make solution with brake system, like brake friction materials or disc surface. However the countermeasure of excitation system also have a lot of risk. It could occur side-effects of braking performance, and need to reverify brake noise like Creep-groan, Groan, Squeal, Judder and so on. In conclusion, It is very important making robust chassis system in initial vehicle development stage. This paper is about rear brake grind noise path analysis and countermeasure of chassis system. There are two steps to analysis. First step is impact hammer test like FRF, MODAL test.
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