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Viewing 1 to 30 of 2421
2017-04-04
Event
This session addresses transmission noise, vibration, rattle issues and design solutions.
2017-01-15
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.
2016-11-15
Event
All aspects of small engine related noise and vibration are covered in this session including: generation, experimental techniques, measurement, numerical analysis, NVH materials, source identification, NVH quality and novel solutions.
2016-11-15
Event
All aspects of small engine related noise and vibration are covered in this session including: generation, experimental techniques, measurement, numerical analysis, NVH materials, source identification, NVH quality and novel solutions.
2016-11-08
Technical Paper
2016-32-0041
Chao-Kai LI, Jia-Siou wu, Yuh-Yih Wu
Today, motorcycle is one of the main noise pollution in Asia. In addition, the design of motorcycle muffler is closely related with how noise is made as the regulation is getting crucial these years. Therefore, Transmission Loss (TL) is an important index to evaluate the characteristic of muffler, but conventional trial and error method results in time wasting muffler tests. In this paper, in order to shorten the development period, Ricardo WAVE software is used to discuss the simulate analysis TL of motorcycle muffler. In this paper uses the huge heavy motorbike (400cc) made from manufacture to simulate TL. Due to the complex interior design of the target muffler which is mainly made of simple elements, this research put simulate analysis on simple elements like single chamber, non-coaxial and insert expansion chamber, clapboard chamber and sound absorbing materials at first place. There are three goals in this research.
2016-11-08
Technical Paper
2016-32-0043
Bernhard J. Graf, Christian Hubmann, Markus Resch, Mehdi Mehrgou
Beside hard facts as performance, emissions and fuel consumption especially the brand specific attributes such as styling and sound are very emotional, unique selling prepositions. To develop these emotional characters, within the given boundary conditions of the future pass-by regulation, it is necessary to define them at the very beginning of the project and to follow a consequent development process. The following paper shows examples of motorcycle NVH development work on noise cleaning and sound engineering using a hybrid development process combining front loading, simulation and testing. One of the discussed solutions is the investigation of a piston pin offset in combination with a crankshaft offset for the reduction of friction. The optimization of piston slap noise as a result of the piston secondary motion was performed by simulation. As another example a simulation based development was performed for the exhaust system layout.
2016-11-08
Technical Paper
2016-32-0044
Gaku Naoe
One of the issues involved in compression ignition combustion is the increase in combustion noise from engine mechanical systems caused by rapid combustion. When using natural gas of high ignition temperature in the fuel, the compression ratio is increased relative to gasoline, and combustion becomes more rapid. The present research pursues the issue of noise by clarifying the distinctive features of combustion noise through tests focused on the two topics of stroke bore ratio (S/B ratio), and ignition timing. In order to verify S/B ratio and in-cylinder pressure change rate, combustion noise was measured in five types of engine with the same displacement and the S/B ratio varying from 0.8 to 2.1. The test results seemed that the effect of input load reduction due to the smaller bore caused a reduction in combustion noise at the same in-cylinder pressure change rate.
2016-11-08
Technical Paper
2016-32-0042
Bhaarath Rajagopal Jeyapaal, Vamsi Krishna, Kannan Marudachalam
Vibrations have become an increasingly important attribute for determining the quality of automotive products. Particularly, this becomes more acute in the case of tactile vibrations of powered two-wheeler – motorcycles and scooters. This paper deals with vibrations of a scooter vehicle. Scooters are normally a two-wheeler with a four stroke single cylinder spark ignited engine. Vibrations of a scooter are mainly caused by the inertial imbalance forces of the engine, combustion forces and road undulations. Vibrations due to road undulations are mostly reduced by toggle link mechanism, resilient mounts of the engine and the shock absorbing suspension of the frame. The power train assembly is designed in such a way that the inertial imbalance forces in the power train assembly are distributed at a required angle called the ellipse angle.
2016-10-17
Technical Paper
2016-01-2355
Sivanesan M, Jayabalaji G
Analytical and numerical study is carried out to study the behavior of stick-slip and judder phenomenon during engaging and disengaging of the automotive clutch. For this, a four degree of freedom torsional power train lumped mass model is developed. This torsional vibration system includes engine-flywheel, clutch, gear box and vehicle drive line, which are connected to each other by shafts. Equation of motion of the system is developed and initially a stability analysis is carried out for various gradients of coefficient of friction using eigen value analysis. Later, a numerical simulation is carried out to analyze the judder and stick-slip phenomenon using commercially available mathematical tool MATLAB. It is observed that the clutch stick-slip is increased with increase in external torque and clutch pressure fluctuations.
2016-10-17
Technical Paper
2016-01-2178
Daniela Siano, Gerardo Valentino, Fabio Bozza, Arturo Iacobacci, Luca Marchitto
In this paper, a downsized twin-cylinder turbocharged spark-ignition engine is experimentally investigated at test-bench in order to verify the potential to estimate the peak pressure value and the related crank angle position based on vibrational data acquired by an accelerometer sensor. Purpose of the activity is to provide the ECU of additional information to establish a closed-loop control of the spark timing, on a cycle-by-cycle and cylinder-by-cylinder basis. In this way, an optimal combustion phasing can be more properly accomplished in each engine operating condition. Vibrational data are also employed to have information on cycle-by-cycle variations (CCVs) of the pressure peak. More sophisticated techniques for the control of the cycle dispersion are also foreseen. To this aim, engine behavior is firstly characterized in terms of average thermodynamic and performance parameters and CCVs at high-load operation.
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.
2016-09-27
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
2016-01-2096
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
2016-01-8121
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
2016-01-8116
Mrudula Uday Orpe, Monika Ivantysynova
Abstract Mobile Earth Moving Machinery like Skid-steer loaders have 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
2016-01-8101
Yoshimune Mori, Akifumi Yoshimura, Nobutaka Tsujiuchi, Akihito Ito, Atsushi Fujimoto, Zenzo Yamaguchi, Koichi Honke
Abstract In a typical mechanical product such as an automobile or construction machinery, it is important to identify deformation modes, for which experiments and analyses can result in significant improvements. It is also important to consider how to improve the structure with high rigidity by using a technique such as the strain energy method in conventional design and development. However, the abovementioned method often generates conflicting results with regard to weight saving and cost reduction of development requirements. Transfer path analysis (TPA) using the finite element method (FEM) is an effective way to reduce noise and vibration in the automobile with respect to these issues. TPA can reveal the transfer path from the input to the response of the output point and the contribution of the path, and to efficiently consider improved responses.
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.
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
Journal Article
2016-01-1931
Aaron Völpel, Georg Peter Ostermeyer
Abstract In today’s research and development of brake systems the model-based prediction of complex vibrations and NVH phenomena plays 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
Journal Article
2016-01-1939
Toshikazu Okamura
Abstract Brake judder is one of the most serious problems in automotive-brake systems. It is basically a forced vibration caused by the friction-surface geometry of a brake disc, and therefore, disc rotors play a significant role in judder. There are two types of judder: cold and hot. Hot judder is caused by the thermo-mechanical deformation of a brake disc due to high-speed braking. There are several shapes of deformation, e.g., coning and circumferential waviness. Circumferential waviness is caused by thermo-mechanical buckling and typically found as a butterfly shape in a 2nd rotational-order and hot-spotting. In a previous paper, two groups of disc castings with different material homogeneity were machined intentionally to have two kinds of dimensional variations.
2016-09-18
Journal Article
2016-01-1911
Philippe Dufrenoy, Vincent Magnier, Yassine WADDAD, Jean-Francois Brunel, Gery DE SAXCE
Abstract 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. A multiscale strategy is propose to integrate the microscopic behavior of the interface in a macroscopic numerical model. Semi-analytical resolution is done on patches at the contact scale while FEM solution with contact parameters embedded the solution at the microscale is used. Asperities and plateaus are considered at the contact interface.
2016-09-01
Magazine
Solving the Greenhouse Gas puzzle While automakers and policymakers debate the TAR, engineers and product planners prepare for the steep climb to meet GHG and CAFE rules beyond 2022. Revving up thermal characterization in the component lab The latest generation of high-speed infrared cameras can capture airbag deployments and other fast-moving actions quickly and accurately. C3 consortium aims for soot solution A newly formed group of companies led by CFD specialists Convergent Science targets exhaust particulate reduction in the combustion chamber. Inside the autonomous vehicle With less focus on driver needs, comfort, safety, and occupant productivity will become key. Editorial: Bad gas?
2016-07-27
WIP Standard
J1455
The scope of this recommended practice encompasses the range of environments which influence the performance and reliability of the electronic equipment designed for heavy duty on and off road vehicles, as well as any appropriate stationary applications which also use these vehicle derived components. A few examples of such vehicles are on and off highway trucks, trailers, buses, construction equipment and agricultural equipment including implements.
2016-07-12
Standard
AMS3807C
This specification covers aluminum foil tape with a pressure sensitive adhesive.
2016-06-28
Standard
J1598_201606
This SAE Recommended Practice is applicable to all liquid-to-gas, liquid-to-liquid, gas-to-gas, and gas-to-liquid heat exchangers used in vehicle and industrial cooling systems. This document outlines the test to determine durability characteristics of the heat exchanger from vibration-induced loading.
2016-06-16
Standard
AS5391A
Accelerometers are transducers, or sensors, that convert acceleration into an electrical signal that can be used for airframe, drive, and propulsion system vibration monitoring and analysis within vehicle health and usage monitoring systems. This document defines interface requirements for accelerometers and associated interfacing electronics for use in a helicopter Health and Usage Monitoring System (HUMS). The purpose is to standardize the accelerometer-to-electronics interface with the intent of increasing interchangeability among HUMS sensors/systems and reducing the cost of HUMS accelerometers. Although this interface was specified with an internally amplified piezoelectric accelerometer in mind for Airframe and Drive Train accelerometers, this does not preclude the use of piezoelectric accelerometer with remote charge amplifier or any other sensor technology that meets the requirements given in this specification.
2016-06-15
Technical Paper
2016-01-1821
Lin Du, Mats Abom, Mikael Karlsson, Magnus Knutsson
Abstract To tune the acoustics of intake systems resonators are often used. A problem with this solution is that the performance of these resonators can be affected a lot by flow. First, for low frequencies (Strouhal-numbers) the acoustic induced vorticity across a resonator inlet opening will create damping, which can reduce the efficiency. Secondly, the vorticity across the opening can also change the end-correction (added mass) for the resonator, which can modify the resonance frequency. However, the largest problem that can occur is whistling. This happens since the vortex-sound interaction across a resonator opening for certain Strouhal-numbers will amplify incoming sound waves. A whistling can then be created if this amplified sound forms a feedback loop, e.g., via reflections from system boundaries or the resonator. To analyse this kind of problem it is necessary to have a model that allows for both sound and vorticity and their interaction.
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