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Viewing 1 to 30 of 9454
2017-03-25
Book
This is the electronic format of the Journal.
2016-12-05 ...
  • December 5-16, 2016 (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.
2016-11-29 ...
  • November 29-December 6, 2016 (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.
2016-10-26
Event
This session 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.
2016-10-17
Technical Paper
2016-01-2343
Mark Devlin, Darryl Williams, Michael Glasgow, Karen Hux, Aaron whitworth, Timothy Cameron
Improving vehicle fuel efficiency is a key market driver in the automotive industry. Typically lubricant chemists focus on reducing viscosity and friction to reduce parasitic energy losses in order to improve automotive fuel efficiency. However, in a transmission other factors may be more important. If an engine can operate at high torque levels the conversion of chemical energy in the fuel to mechanical energy is dramatically increased. However high torque levels in transmissions may cause NVH to occur. The proper combination of friction material and fluid can be used to address this issue. Friction in clutches is controlled by asperity friction and hydrodynamic friction. Asperity friction can be controlled with friction modifiers in the ATF. Hydrodynamic friction control is more complex because it involves the flow characteristics of friction materials and complex viscosity properties of the fluid.
2016-10-17
Technical Paper
2016-01-2344
Darryl Williams, Jeffrey Guevremont, John Perry
Good shift quality in automatic transmissions is important for fuel efficiency, driver comfort, and performance. Maintaining this performance over the life of the vehicle is also important. Typical lubricant development focuses on reducing viscosity and friction in order to reduce parasitic losses. In an automatic transmission, other factors are also important for good performance, primarily due to the shifting and torque converter clutches. A high level of friction is desirable for torque capacity, and a steady decrease in friction as sliding speed (rpm) decreases is necessary for both good shift feel and good friction system durability over the lifetime of the vehicle. Friction material surface characteristics have a dramatic impact on changes in friction level with sliding speed (the mu-v curve) and the performance of the friction system is heavily impacted by changes in these characteristics.
2016-10-17
Technical Paper
2016-01-2345
Guoyu FENG
To study the static and dynamic characteristics of thrust rod, based on multi-body dynamics and finite element method for static and dynamic characteristics of the thrust rod were analyzed. The establishment of a dynamic simulation model of vehicle and the road, in the extreme conditions of the thrust rod loads were calculated. Thrust rod finite element model is established, according to the calculation result of the load and test data of rubber, stiffness, strength and modal analysis, and verified by test, gained its deformation, stress distribution and low-order natural frequency and mode shape. The results provide a theoretical basis for the design and optimization of the thrust rod.
2016-09-30 ...
  • September 30, 2016 (8:30 a.m. - 4:30 p.m.) - Scottsdale, Arizona
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.
2016-09-29 ...
  • September 29, 2016 (8:30 a.m. - 4:30 p.m.) - Scottsdale, Arizona
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.
2016-09-27
Technical Paper
2016-01-8121
Riccardo Bianchi, Addison Alexander, Andrea Vacca
Vibrations at the cabin or at the implements of construction machinery represents important drawbacks from the points of view of machine productivity, safety and operator comfort. Oscillations of these machines are particularly relevant due to the absence of shock absorbers, typical of many machines such as wheel loaders, and their use in uneven ground conditions. Several hydraulic solutions have been proposed in the past to reduce oscillations at both the cabin or at the machine boom. Particularly, cabin oscillations can be attenuated by properly counteracting the exciting oscillatory forces from the tires with motion of the boom. Many state of the art machine utilize a passive methods to implement this strategy. The present work introduces a novel active solution, based on the control of the boom actuator without involving modifications of the standard hydraulic system.
2016-09-27
Technical Paper
2016-01-2096
Simon Schnieders, Dirk Eickhorst
Drilling of high-strength titan material and composites in combination creates complex challenges in order to achieve required productivity and quality. Long spiral chips are characteristically for the titan drilling process, which leads to e.g. chip accumulation, high thermomechanical load, surface damages and excessive tool wear. The basic approach is the substitution of today’s peck-drilling as current solution to this problem and the implementation of a vibration assisted drilling, so called micro-peck-drilling-process, to generate a kinematic chip breakage in a significant more efficient way. To meet perfectly the requirements regarding rates, quality and automation level, Broetje-Automation as system integrator has investigated and developed the implementation of different alternative high-performance systems and methods to approach the optimal oscillation movement of the tool.
2016-09-27
Technical Paper
2016-01-2097
Sylvain Laporte, Cosme De Castelbajac, Mathieu Ladonne
The Vibration Assisted Drilling (VAD) process has been implemented in Automated Drilling Units (ADU) on an industrial scale for almost a decade. Today more than 11000 ADUs are equiped with VAD systems and currently used on aircraft assembly lines. As well as drawing up a short report on the use of this new process, the authors make an assessment on new challenges that VAD has to face up. Indeed production rates are increasing and ADU manufacturers improve their technologies, one of the most recent and major development concerning the electrical motorization of the machines. These evolutions are as many opportunities for the VAD provided you have a clever understanding as well as an expert knowledge of the process. Thus the authors propose a new dynamic model of the whole VAD system which integrates the behavior of the part, cutting tool/material pair and the machine. The confrontation of model results and experimental validation tests demonstrates the relevance of the works.
2016-09-27
Technical Paper
2016-01-8101
Yoshimune Mori, Akifumi Yoshimura Esq, Nobutaka Tsujiuchi, Akihito Ito, Atsushi Fujimoto, Zenzo Yamaguchi, Koichi Honke
In a typical mechanical product such as automobile and construction machinery, it is a general method that identify the deformation mode in which significant improvement target of contributing to the response from the experiments and analysis solution and consider the structure of the proposed improvements in the way of high rigidity by using a technique such as strain energy method in the conventional design and development. In however the above-mentioned method, it is often a conflicting results with weight saving and cost reduction that were required from development. Transfer path analysis (TPA) using FEM is an effective method of reducing noise and vibration of the automobile with respect to these issues. TPA can reveal that the transfer path from the input to the response of the evaluation point and the contribution of the path and consider the improvement of the response efficiently.
2016-09-27
Technical Paper
2016-01-8116
Mrudula Uday Orpe, Monika Ivantysynova
Mobile Earth Moving Machinery like Skid-steer loaders have a tight turning radius in limited spaces due to a short wheelbase which prevents the use of suspensions in these vehicles. The absence of a suspension system exposes the vehicle to ground vibrations of high magnitude and low frequency. Vibrations reduce operator comfort, productivity and life of components. Along with vibrations, the machine productivity is also hampered by material spillage which is caused by the tilting of the bucket due to the extension of the boom. The first part of the paper focuses on vibration damping. The chassis’ vibrations are reduced by the use of an active suspension element which is the hydraulic boom cylinder which is equivalent to a spring–damper. With this objective, a linear model for the skid steer loader is developed and a state feedback control law is implemented.
2016-09-27
Technical Paper
2016-01-8143
Jerry Syms, Theresia Manns, Björn Bergqvist
The noise generated by the flow of air past a transport truck is a key design factor for the manufacturers of these vehicles as the sound levels in the cabin are a significant component of driver comfort. This paper describes a demonstration study to measure the in-cabin aeroacoustic environment of a full-scale cab-over tractor in the NRC 9 m Wind Tunnel. Acoustic instrumentation was installed inside the tractor to record cabin noise levels and externally to acquire tunnel background noise data. Using a microphone mounted on the driver’s-side tunnel wall as a reference to remove variations in background noise levels between data points, differences in cabin noise levels were able to be detected when comparing the tractor with different configurations. The good repeatability of the data allowed for differences of as little as 0.5dB to be measured.
2016-09-27
Technical Paper
2016-01-2136
Oliver Pecat, Tebbe Paulsen, Philipp Katthöfer, Ekkard Brinksmeier, Sascha Fangmann
Insufficient chip extraction often leads to disruptions of automated drilling processes and degraded surface qualities. One opportunity to avoid chip accumulation is based on a cinematically enforced chip breakage caused by sinusoidal axial oscillations of the drilling tool. Recent investigations have shown that the quality of chip extraction is, amongst others, considerably depending on the chip shape and mass which are defined by the cutting parameters feed, amplitude and number of oscillation per revolution. So far only mechanical systems in the form of tool holders have been available on the market, which are restricted to a fixed number of oscillations per revolution (oscillation frequency is coupled to the spindle speed). In the present study a spindle with magnetic bearings was used which allows to adjust the oscillation frequency independently of the spindle speed and therefore enables all opportunities to affect the generated chip shapes.
2016-09-20
Technical Paper
2016-01-2009
Natasha Barbely, Narayanan Komerath, Nandeesh Hiremath
Coaxial rotors are finding use in advanced rotorcraft concepts. Combined with lift offset rotor technology, they offer a solution to the problems of dynamic stall and reverse flow that often limit single rotor edgewise forward flight speeds. Lower tip speed means reduced high speed impulsive noise. The need for an anti-torque tail rotor is eliminated, a major boon during operation in confined areas. However, the operation of two counter-rotating rotors in close proximity generates many possibilities for aerodynamic interactions between rotor blades, blades and vortices, and between vortices. The parameter design space is very large, and requires efficient computations as well as basic experiments to explore important physics determines performance, loads, and acoustics. Computations are done on the classic Harrington/Dingeldein rotor test case from the 1950s using the ROTUNS Navier Stokes code as well as the NASA OVERFLOW and/or HELIOS codes.
2016-09-19 ...
  • September 19-20, 2016 (8:30 a.m. - 4:30 p.m.) - Shanghai, China
Training / Education Classroom Seminars
The sound package materials for vehicle noise control seminar provides a detail and thorough analysis of three different classes of acoustical materials – namely absorbers, barriers, and dampers, how they are different from each other, and acoustical properties that materials should possess for optimum vehicle noise control. The seminar addresses new advances in acoustical materials, primarily in absorption materials that impact the vehicle acoustics. The seminar covers ways to evaluate the acoustical performance of these materials using different test methods, including material, component, and vehicle level measurements.
2016-09-18
Technical Paper
2016-01-1944
Seongjoo Lee, JeSung Jeon, ShinWook Kim, ShinWan Kim, Seong Rhee, Wan Gyu Lee, Young Sun Cho, Jeongkyu Kim
It is widely known that brake squeal repeatability and reproducibility are difficult to achieve whether a run on a vehicle on the road, a vehicle on a chassis dynamometer or a single brake on a noise dynamometer. At one time, the same brake may generate only low-frequency squeals (1.5 - 5 kHz) and at another time, only high-frequency squeals (5 - 20 kHz). More specifically, on a chassis dynamometer, the left side may produce only low-frequency squeals (or high-frequency squeals) while the right side produces only high-frequency squeals (or low-frequency squeals), or mixed squeals at different rates. The same phenomenon is observed when brakes are run on a noise dynamometer; more low-frequency squeals at one time or more high-frequency squeals at another time on an apparently same brake system. This study was undertaken to find out what causes these discrepancies.
2016-09-18
Technical Paper
2016-01-1933
Mingzhuo Li, Dejian Meng, Lijun Zhang
Brake judder severely affects the riding comfort and safety of vehicle. For the brake corner system, a rigid-flexible coupling model are established based on ADAMS. In the model, brake pads, caliper, anchor and knuckle are flexible body, and the contacts between pads and disc and the contact between pads and caliper are defined in detail. Meanwhile, the vibration acceleration of the brake corner components and the contact forces between disc and pads are used as evaluation index and the evaluation system of brake judder are improved. The analysis results show that the novel model and evaluation system can be used to predict brake judder effectively.
2016-09-18
Technical Paper
2016-01-1911
Philippe Dufrenoy
A multiscale model of a disc brake including material and surface heterogeneities Y. Waddad; V. Magnier; P. Dufrénoy* ; G de Saxcé University of Lille Cité scientifique Avenue Paul Langevin F-59655 Villeneuve d’Ascq Cedex * Corresponding author : philippe.dufrenoy@univ-lille1.fr During friction it is well known that the real contact area is much lower to the theoretical one and that it evolves constantly during braking. It influences drastically the system’s performance. Conversely the system behavior modifies the loading conditions and consequently the contact surface area. This interaction between scales is well-known for the problematic of vibrations induced by friction but also for the thermomechanical behavior. Indeed, it is necessary to develop models combining a fine description of the contact interface and a model of the whole brake system. This is the aim of the present work. The macroscopic model is obtained with Finite Element analysis.
2016-09-18
Technical Paper
2016-01-1931
Aaron Völpel, Georg Peter Ostermeyer
In today’s research and development of brake systems the model-based prediction of complex vibrations and NVH phenomena play an important role. Despite the efforts, the high dimensional computational simulation models only provide a limited part of the results gained through experimental measurements. Several reasons are discussed by the industry and academic research. One potential source of these inadequacies is the very simple formulation of the friction forces in the simulation models. Due to a significant shorter computation time (by orders of magnitude), the complex eigenvalue analysis has been established, in comparison to the transient analysis, as the standard method in the case of industrial research, where systems with more than one million degrees of freedom are simulated.
2016-09-18
Technical Paper
2016-01-1915
Meechai Sriwiboon, Seong Rhee, Kritsana kaewlob, Nipon Tiempan, Rungrod Samankitesakul
Two formulations have been selected and tested for this investigation; Low-Copper NAO and Copper – Free NAO. Each formulation was processed to achieve 3 levels of porosity; 12, 17 and 22%. Each sample was tested for hardness (HRR, HRS, and HRL), natural frequencies and compressibility plus performance testing for friction, wear and brake squeal. This paper describes correlations or lack of them between all the measurements.
2016-09-18
Technical Paper
2016-01-1921
Yusuke Sunagawa, Tsuyoshi Kondo
Brake squeal noise is generally classified into two vibration modes of disc. One is called “out-of plane mode” which vibrates in disc’s out-of-plane direction. The other is “In-plane mode” which vibrates in disc’s in-plane direction, it means the disc is contracted partially or is extended. There are few “In-plane noise” analysis reports from Disc pad standpoint, so it has been unclear how disc pad contributes to “In-plane mode” until now. This paper confirms that we successfully analyzed direct pad vibration mode by laser scanning under in-plane mode condition. Based on these results, we assume that pad stiffness affected in-plane mode and carried out validation tests.
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