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Viewing 61 to 90 of 9351
2016-06-15
Technical Paper
2016-01-1779
Sergio Carvajal, Daniel Wallner, Reinhard Helfrich, Michael Klein
Abstract Numerical methods for brake squeal analysis are widely accepted in industry. The use of complex eigenvalue analysis is a successful approach to predict the appearance of squeal noise. Using simulation in an early design stage reduces time to market, saves costs, and improves the physical behavior and robustness of the brake system. State of the art of brake simulation comprises sampling for many parameter sets in a wide range of interesting values. Based on high performance, stability maps can be created in short time containing many results, which gives a deep insight into the brake behavior under varying parameters. An additional benefit of sampling is the possibility to detect parts with high potential for improving the NHV comfort. In the sequel, mathematical optimization methods like topology optimization or shape optimization are used for systematic improvements.
2016-06-15
Technical Paper
2016-01-1780
Francesca Ronzio, Theophane Courtois
Abstract In automotive acoustics, body NVH design is traditionally carried out without considering the acoustic trim parts. Nevertheless, the vibro-acoustic interaction of body structure and insulation trim cannot be neglected in the middle frequency range, where structure borne propagation might still be dominating and where classical statistical approaches are generally not able to represent the influence of local changes in stiffness and damping. This, together with the market requirement of lightweight and more efficient sound package solutions, is leading the CAE engineers to evaluate new design approaches dedicated to vehicle components such as dash or floor systems, for which the multi-physics interaction between damping, body stiffness and trim impedance is important.
2016-06-15
Technical Paper
2016-01-1783
Oliver Engler
Mercedes-AMG GmbH specializes in unique, high-performance vehicles. The image of AMG as the successful performance brand of Mercedes-Benz is reflected in its impressive successes in the world of motorsport and its unique vehicles. One of these vehicles is the SLS AMG Coupé Electric Drive. After an elaborate series of tests as well as numerous test drives, we have created the SLS eSound which captures the exceptional dynamism of this unique super sports car with electric drive. Starting with a characteristic start-up sound, which rings out on pressing the "Power" button on the AMG DRIVE UNIT, the occupants can experience a tailor-made driving sound for each driving situation: incredibly dynamic when accelerating, subdued when cruising and as equally characteristic during recuperation. The sound is not only dependent on road speed, engine speed and load conditions, but also reflects the driving situation and the vehicle's operating state with a suitable driving noise.
2016-06-15
Technical Paper
2016-01-1800
Xavier Carniel, Anne Sanon
Abstract The control of sound fields radiated by vibrating structures in a passenger compartment, (especially structures connected to different organs like the engine powertrain, the fan motor unit, seats, the steering column, electrical motors more and more, etc.) is among the functions of the automotive manufacturers. The absence of physical prototypes in the development phase systems led OEMs1 to use tests results obtained on benches following technical specifications from manufacturers. The transition "bench to vehicle" for vibro- acoustic behaviour sets many challenges that this standard intends to clear up. This standard specifies the experimental method to transpose the dynamic forces generated by the global movements of an active component between the vehicle and a test bench. The efforts are first measured on test benches and then transposed from test bench towards the vehicle. The standard is now a French standard (XP R 19-701) and is submitted to ISO process [1].
2016-06-15
Technical Paper
2016-01-1802
Mehdi Mehrgou, Franz Zieher, Christoph Priestner
Abstract Recently, hybrid and fully electric drives have been developing widely in variety, power and range. The new reliable simulation approaches are needed, in order to meet the defined NVH targets of these systems and implementing CAE methods for front loading, Design Validation Process (DVP). This paper introduces the application of a novel NVH analysis workflow on an electric vehicle driveline including both electromagnetic and mechanical excitations for an absolute evaluation of the NVH performance. At first, the electromagnetic field is simulated using FEM method to extract the excitations on the stator, rotor bearings as well as the drive torque. Then, the multibody dynamic model of the driveline is built-up, driven by this torque. The effect of eccentricity and skew angle of rotor in electromagnetic excitations are shown.
2016-06-15
Technical Paper
2016-01-1835
Albert Albers, Fabian Schille, Matthias Behrendt
Abstract In terms of customer requirements, driving comfort is an important evaluation criterion. Regarding hybrid electric vehicles (HEVs), maneuver-based measurements are necessary to analyze this comfort characteristic [1]. Such measurements can be performed on acoustic roller test benches, yielding time efficient and reproducible results. Due to full hybrid vehicles’ various operation modes, new noise and vibration phenomena can occur. The Noise Vibration Harshness (NVH) performance of such vehicles can be influenced by transient powertrain vibrations e.g. by the starting and stopping of the internal combustion engine in different driving conditions. The paper at hand shows a methodical procedure to measure and analyze the NVH of HEVs in different driving conditions.
2016-06-15
Journal Article
2016-01-1844
Jonathan Millitzer, Dirk Mayer, Roman Kraus, Matthias Schmidt
Abstract Current developments in the automotive industry such as downsizing, the use of cylinder deactivation and consistent lightweight construction increasingly enable the application of active control systems for the further reduction of noise and vibration in vehicles. In the past few years, different configurations of actuators and sensors for the realization of an active control system have been investigated and evaluated experimentally. Active engine mounts, inertial mass actuators and structural integrated actuators can be used to reduce either structural vibrations or the interior noise level. As a result, a variety of different topology concepts for the realization of an active control system arises. These can be divided into an active vibration control scenario, the direct influence of the sound field with loudspeakers or the application of structural actuators for the reduction of the interior sound pressure.
2016-06-15
Technical Paper
2016-01-1771
Manish Chhabra
Abstract By reducing overall noise emanating from Engine at design phase, permits to reduce both time-to-market and the cost for developing new engines. In order to reduce vibration and radiated noise in engine assembly, oil pan is one of the most critical components. This study explains the key-steps that are executed to optimize the oil pan design for 4-cylinder diesel engine by improving Normal Modes, modified Topology, reduced Forced Frequency Response and ATV analysis for reducing its noise radiation. Using Multi-body tool crankshaft forces were generated and the FE model of Base Design was analysed for its noise radiation and panel contribution was done for finding the most radiating panels using Boundary Element Method approach. A series of iterative optimization were carried out with commercial software.
2016-06-15
Technical Paper
2016-01-1776
Alexander Rabofsky, Alexander Koeck, Martin Mittermaier
Abstract Lightweight vehicle design causes special demands for functional NVH design. The reduction of weight by reducing material thickness, enabled by new alloys, the combination of materials and new materials increases the sensitivity of a vehicle body to the vibrational and acoustical response of external forces like powertrain or road and wind excitation. To be able to fully raise lightweight potentials design has to be driven closer to functional boundaries, putting higher demands on the accuracy of the prediction by simulation. For a robust design a very broad view on several loadcases is needed to make sure that by optimization on one target no other target is violated. In this paper, optimization strategies for complex NVH load-cases should be investigated in detail. In reality, load-cases, excitations as well as boundary conditions are very often complex and complicated.
2016-06-15
Technical Paper
2016-01-1854
Johannes Seifriedsberger, Rudolf Wichtl, Helmut Eichlseder
Abstract The present article is concerned with the investigation of the engine noise induced by the piston slap of an actual passenger car Diesel engine. The focus is put on the coherence of piston secondary movement, impact of the piston on the cylinder liner, generated structure-borne noise excitation of the engine structure and the occurring acceleration on the engine surface. Additionally, the influence of a varying piston-pin offset and piston clearance is evaluated. The analyses are conducted using an elastohydrodynamic multi-body simulation model, taking into account geometry, stiffness and mass information of the single components as well as considering elastic and hydrodynamic behavior of the piston-liner contact. A detailed description of the simulation model will be introduced in the article. The obtained results illustrate the piston secondary motion and the related structure-borne noise on the engine surface for several piston-pin offsets and piston clearances.
2016-06-15
Technical Paper
2016-01-1804
Stefan Becker, Katrin Nusser, Marco Oswald
Abstract Aim of the ongoing development of passenger cars is to predict the interior acoustics early in the development process. A significant noise component results from the flow phenomena in the area of the side window. Wind noise is a physical problem that involves the three complicated aspects each governed by different physics: The complex turbulent flow field in the wake of the a-pillar and the side mirror is characterized by velocity and pressure fluctuations. The flow field generates sound which is transmitted into the passenger cabin. In addition to that, it excites the structure, resulting in a radiation of structure-borne noise into the interior of the car. Therefore, the sound generation is governed by fluid dynamics of the air flow. The sound transmission through the structure due to vibrations is determined by structural mechanics of the body structure. The sound propagation inside the cabin is influenced by interior room acoustics.
2016-06-15
Technical Paper
2016-01-1796
Aurélien Cloix, Jean-Luc Wojtowicki
Abstract The current paper is based on the French research program TESSA (“Transfert des Efforts des Sources Solidiennes Actives”). A specific task within TESSA project consists in the characterization of the measurements variability between several laboratories, of the blocked forces on a water pump of a heat engine. This paper focuses only on the measurements carried out at Vibratec laboratory. Two kinds of measurements have been carried out: direct measurements, using force sensors, which is the target of the inter-laboratory measurements, and an inverse method without force sensor requirements. Reproducibility and repeatability tests have been done in order to quantify the measurement variability within the same laboratory, in preparation for the inter-laboratory disparity analysis.
2016-06-15
Journal Article
2016-01-1808
Manfred Kaltenbacher, Andreas Hüppe, Aaron Reppenhagen, Matthias Tautz, Stefan Becker, Wolfram Kuehnel
Abstract We present a recently developed computational scheme for the numerical simulation of flow induced sound for rotating systems. Thereby, the flow is computed by scale resolving simulations using an arbitrary mesh interface scheme for connecting rotating and stationary domains. The acoustic field is modeled by a perturbation ansatz resulting in a convective wave equation based on the acoustic scalar potential and the substational time derivative of the incompressible flow pressure as a source term. We use the Finite-Element (FE) method for solving the convective wave equation and apply a Nitsche type mortaring at the interface between rotating and stationary domains. The whole scheme is applied to the numerical computation of a side channel blower.
2016-06-15
Technical Paper
2016-01-1836
Sylvestre Lecuru, Pascal Bouvet, Jean-Louis Jouvray, Shanjin Wang
Abstract The recent use of electric motors for vehicle propulsion has stimulated the development of numerical methodologies to predict their noise and vibration behavior. These simulations generally use models based on an ideal electric motor. But sometimes acceleration and noise measurements on electric motors show unexpected harmonics that can generate acoustic issues. These harmonics are mainly due to the deviation of the manufactured parts from the nominal dimensions of the ideal machine. The rotor eccentricities are one of these deviations with an impact on acoustics of electric motors. Thus, the measurement of the rotor eccentricity becomes relevant to understand the phenomenon, quantify the deviation and then to use this data as an input in the numerical models. An innovative measurement method of rotor eccentricities using fiber optic displacement sensors is proposed.
2016-06-15
Journal Article
2016-01-1815
Augusto Della Torre, Gianluca Montenegro, Angelo Onorati
Abstract In the last decades numerical simulations have become reliable tools for the design and the optimization of silencers for internal combustion engines. Different approaches, ranging from simple 1D models to detailed 3D models, are nowadays commonly applied in the engine development process, with the aim to predict the acoustic behavior of intake and exhaust systems. However, the acoustic analysis is usually performed under the hypothesis of infinite stiffness of the silencer walls. This assumption, which can be regarded as reasonable for most of the applications, can lose validity if low wall thickness are considered. This consideration is even more significant if the recent trends in the automotive industry are taken into account: in fact, the increasing attention to the weight of the vehicle has lead to a general reduction of the thickness of the metal sheets, due also to the adoption of high-strength steels, making the vibration of the components a non negligible issue.
2016-06-15
Technical Paper
2016-01-1806
Sumon Sinha, Farokh Kavarana, Dan Williams, Kazuya Asao
Abstract A high performance rigid airfoil profile sunroof wind deflector has been developed for high speed freeway driving with the sunroof open. This deflector is clearly superior to the conventional bar type deflector and less expensive compared to tall flexible fabric mesh deflectors applied on high end vehicles today. It provides superior speech intelligibility under high speed driving with sunroof open. The criterion for designing this deflector was to get the highest airspeed possible to span the sunroof opening under all conditions. The customized shape also utilizes flow unsteadiness, including those at the onset of buffeting, in order to condition the shear layer. The airfoil profiled deflector yielded superior mid and high frequency acoustic performance with acceptable low frequency performance. A shorter airfoil deflector was sufficient to keep the external airflow from entering the forward tilted sunroof opening on a mid-size SUV under test.
2016-06-15
Technical Paper
2016-01-1826
Roman Gartz, Detlev Rammoser, Matthew Maunder
Abstract The transfer characteristics, location of the mounting points, where the exhaust system is attached to the vehicle structure, and the level of excitation forces have a significant contribution to the overall interior noise. The aim of this study is to define targets for the excitation forces of the exhaust line in order to identify its contribution to the overall vehicle interior cabin noise in the early vehicle concept phase when the hardware is not yet available. Furthermore, psychoacoustic parameters are calculated, e.g. the articulation index which provide a representation of the human hearing perception. Therefore a software tool was developed in MATLAB to cascade the interior noise contributions of the exhaust system using the corresponding transfer paths. This tool enables a quick prediction of different combinations (different hanger stiffness and other parameters) to evaluate the potential for improvements.
2016-06-15
Journal Article
2016-01-1801
Jonathan Vaudelle, Florian Godard, Florian Odelot, Anne Sanon
Abstract Acoustic comfort inside the vehicle is required whenever a wiper system is in function: front wiper motor noise is of great influence on the global comfort and its perception inside the car is 100% due to transmission of vibrations through wiper system fixation points on the vehicle. As any active source, both car manufacturer and system supplier need to be involved, at early stages of project development, in order to master the vibroacoustic integration of the system into the vehicle. This paper presents an experimental methodology dedicated to the front wiper system that offers the possibility to estimate the acoustic comfort inside the vehicle during project deployment phase, when modifications can still be proposed. Based on the XP-R-19701 standard, the procedure allows to measure, on a bench, the dynamic forces transmitted via the fixation points and details how to transpose them to the vehicle, taking into account the different specificities of the wiper system.
2016-06-15
Journal Article
2016-01-1827
Giorgio Bartolozzi, Marco Danti, Andrea Camia, Davide Vige
Abstract The time to market in the automotive industry is constantly decreasing pushing the carmaker companies to increase the efforts in numerical simulations and to decrease the number of prototypes. In the NVH field, this time constraint reflects in moving the well-established finite element simulations towards the so called “full-vehicle simulations”. Specifically, the CAE techniques should be able to predict the complete behavior of the vehicles in mission conditions, so to reproduce some usual tests, such as the “coast down” test on different roads. The aim of this paper is to present a methodology to improve rolling noise simulations exploiting an integrated full-vehicle approach. An accurate modeling of all the subsystems is needed, with particular attention to the wheels and the suspension systems. Therefore, the paper firstly covers the modeling approach used to obtain the FE models of tires and suspension system.
2016-05-14
Article
Ann Arbor, Michigan is fast becoming the world capital of testing and research for connected cars, automated driving, and safety technology.
2016-05-13
Article
KTR has started up a test bench for large couplings that covers a performance range up to 500,000 N∙m at its headquarters in Rheine.
2016-05-13
Article
T/CCI Manufacturing’s Climatic Wind Tunnel in Decatur, IL allows customers to simulate any real-world condition by controlling humidity, wind, temperature, solar and road conditions up to100 mph.
2016-05-13
Article
A modular area view kit (AVK) from First Sensor aids in the setup of 360° all-around view systems for applications in special vehicles and machines.
2016-05-13
Article
Hermetic Seal Corporation (HSC), a unit of AMETEK Interconnect, has expanded its hermetic sealing capabilities to include state-of-the-art hermetic fiber-optic component manufacture.
2016-05-05
Magazine
New dawn at Honda R&D President Yoshiyuki Matsumoto aims to invigorate Honda's technology and product-development organization with 'full soul.' Automated driving meets regulation: NHTSA and the next 50 years The challenges and opportunities on the road to 'zero deaths' demand a new level of federal automotive safety technical standards, and a new safety-defect reporting and recall system. NHTSA and the U.S. Congress must act boldly and quickly to make it happen. Autonomous driving meets regulation: Hands off, eyes off, brain off Euro NCAP'S president warns that without coherent policies, the growing availability of automated technologies may result in piecemeal technology development-and unintentional consequences. Designer yin meets engineer yang Efficient and effective vehicle development means even closer collaboration between the two former sparring partners.
2016-04-29
Standard
J2531_201604
New methods are available to assist in evaluating the risk of impulse noise-induced hearing loss from inflatable devices, for example, airbags and seat belt pretensioners. This document presents some background on impulse noise measurement techniques and assessment criteria. Related information relative to test details, for example, preamplifier specifications and filtering methods and criteria, will be discussed in a future recommended practice.
2016-04-27
Article
Take-it-to-the-limit testing is typically reserved for vehicle development teams, but Jaguar's route and the sensational topography clearly gave Automotive Engineering good insight into F-Pace's dynamic capabilities and its four-year development.
2016-04-27
Standard
J3060_201604
This SAE Standard serves as a guide for vibration testing procedures of Automotive and Heavy Duty storage batteries.
2016-04-24
Article
Consortium of OEMs and suppliers worked on all fronts, while the SAE Interior Climate Control Committee reopened a suite of draft standards to prepare for possible importation of cars with R-744: CO2 as a refrigerant.
2016-04-20
Article
Experts say Phase Change Material (PCM) formulated for high latent heat capacity can provide cabin warmth for a typical U.S. daily commute, with residual capacity insulated for an EV parked during an eight-hour workday.
Viewing 61 to 90 of 9351

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