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Viewing 31 to 60 of 9398
2016-09-18
Journal Article
2016-01-1911
Philippe Dufrenoy, Vincent Magnier, Yassine WADDAD, Jean-Francois Brunel, Gery DE SAXCE
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.
2016-08-26
Article
dSPACE and BTC Embedded Systems offer a solution that improves test depth for the real-time validation of safety-critical applications with extension of classical test methods, easier compliance with safety standards and optimal integration and cross-platform use.
2016-08-26
Article
The push toward miniaturization in the electronics industry has left designers little or no room for test points, and the expansion of high frequency technologies has resulted in a growing need for test equipment that has the capability to verify these types of very small circuits.
2016-08-26
Article
CNH Industrial and AVL researchers used simulation, test bench, and road testing of a demonstrator vehicle with a WHR system to show significantly reduced fuel consumption.
2016-08-15
Article
The MicReD Power Tester 600A from Mentor Graphics Corp. tests electric and hybrid vehicle (EV/HEV) power electronics reliability during power cycling.
2016-08-14
Article
Using simulators for RDE testing is a new aspect for the technology, experts say.
2016-08-12
Article
Anritsu Co. (Richardson, TX) introduces Cellular Module Test Application (CMTA) software for its Signaling Testers MD8475A/B, which provides test cases to simplify testing chipsets and automotive-related telematics modules used in connected car designs and implementation.
2016-08-11
Standard
AIR1826A
This Aerospace Information Report (AIR) is limited in scope to the general consideration of environmental control system noise and its effect on occupant comfort. Additional information on the control of environmental control system noise may be found in 2.3 and in the documents referenced throughout the text. This document does not contain sufficient direction and detail to accomplish effective and complete acoustic designs.
2016-08-08
Article
The dangers of faulty car airbags recently have become all too clear. The product-liability issues associated with airbags and the largest, most costly automotive recall in history make it essential to characterize them thermally at high speeds and with high levels of sensitivity and accuracy.
2016-08-02
Standard
J1324_201608
This SAE Recommended Practice provides test methods for determining the characteristics of acoustical and thermal materials. Where applicable, methods of test developed by SAE and ASTM have been referenced.
2016-07-31
Article
Delphi Automotive on August 1 announced an extensive autonomous-vehicle pilot program in Singapore, aimed at demonstrating cloud-based fully automated mobility on demand (AMoD) capability “at the [SAE] Level 4 performance level” by late 2019.
2016-07-31
Article
Made of steel and aluminum, NASA's Airvolt test stand was designed and fabricated to help researchers anticipate system integration challenges and verify and validate electric propulsion components.
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.
2016-07-15
Article
Validation testing of the new 2-step VCR by several OEMs has been successful to date and is expanding, as the industry examines more sophisticated solutions to meet CO2 regulations.
2016-07-15
Article
Mississippi State University's Car of the Future, a hybridized Subaru BRZ with advanced software and 3D-priinted innovations, gets an estimated triple-digit mpg while improving acceleration.
2016-07-12
Standard
AMS3807C
This specification covers aluminum foil tape with a pressure sensitive adhesive.
2016-07-05
Article
Pickering Interfaces expands its range of PXI 50Ω 600MHz radio frequency (RF) multiplexers with 18 different configurations including a PXI two slot 32:1 configuration.
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
2016-01-1823
Andrea Grosso, Martin Lohrmann
Abstract Operational Transfer Path Analysis (OTPA) assess the possible ways of energy to transfer from the various sources of excitation to a given target location. Applied to vehicle engineering, the OTPA provides indication about dominant sources and path contributions. However, it can only analyze the actual system under test and cannot predict if an improvement can be achieved by applying a counter measure. A careful interpretation of the measurement results is therefore necessary in order to define an effective engineering solution strategy. In this paper the RMA (Response Modification Analysis) technique is used to facilitate a sensitivity analysis, gaining insight whether energy is likely to be rerouted. This gives additional understanding of OTPA results, indicating which counter measure is most effective. The RMA is applied to a real measurement scenario, showing the advantage of the combination of OTPA with RMA for correctly identifying the relevant sources and paths.
2016-06-15
Technical Paper
2016-01-1805
Florian Zenger, Clemens Junger, Manfred Kaltenbacher, Stefan Becker
Abstract A low pressure axial fan for benchmarking numerical methods in the field of aerodynamics and aeroacoustics is presented. The generic fan for this benchmark is a typical fan to be used in commercial applications. The design procedure was according to the blade element theory for low solidity fans. A wide range of experimental data is available, including aerodynamic performance of the fan (fan characteristic curve), fluid mechanical quantities on the pressure and suction side from laser Doppler anemometer (LDA) measurements, wall pressure fluctuations in the gap region and sound characteristics on the suction side from sound power and microphone array measurements. The experimental setups are described in detail, as to ease reproducibility of measurement positions. This offers the opportunity of validating aerodynamic and aeroacoustic quantities, obtained from different numerical tools and procedures.
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
2016-01-1803
Hannes Frank, Claus-Dieter Munz
Avoiding narrowband components in the acoustic spectrum is one of the most critical objectives in the automotive aeroacoustic optimization process. The underlying physical mechanisms are not completely understood. In a preceding numerical and experimental investigation, we performed large eddy simulations of an early-development stage realistic side-view mirror, where tonal noise was captured and the principle mechanisms were identified. In this contribution, we present simulations on a simplified two-dimensional geometry that is based on these findings. It is shown that the basic flow topology relevant for tonal noise generation on the original side-view mirror as well as the tonal noise source is reproduced in the 2D case. Furthermore, we present comparisons with measurements and the necessity and influence of a splitter plate downstream of the 2D body to avoid large scale vortex shedding.
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
2016-01-1796
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
Technical Paper
2016-01-1798
Quentin Buisson, Jean-Louis Guyader, Serge Puvilland, Xavier Carniel, Maximilien Soenen
Abstract The goal of the present study is to provide a simple method to compare structure borne noise sources in order to choose the most efficient one, considering the transmission of dynamic forces. It is well known that mechanical sources are not only dependent of the source itself but also of the receiving structure, in addition real sources cannot be reduced to a transverse force acting on the structure but more complicated effect like moment excitation must be taken into account. The advantage of the reception plate method is to characterize the source globally by the level of vibration of the reception plate whatever the type of excitation, the idea is basically to characterize mechanical sources as it is done for acoustical sources in reverberant rooms. A reception plate test bench has been developed to determine the power injected by mechanical sources. Two prototype plates have been designed in order to have different receiving mobilities.
2016-06-15
Technical Paper
2016-01-1794
Jonathan Caprile, Claire Chaufour, Pierre Emile Chartrain
Abstract In automotive NVH, the noise generated by a powertrain is still one of the major noise sources especially at low and mid vehicle velocity. For this reason automotive OEMs are continuously focusing on methods to efficiently analyze this noise source. For this purpose, a well-established simulation methodology can provide results thoroughly, within a limited amount of time and with a reduced cost contrary to experiments which are involved in late design phases and are more expensive. This paper aims at presenting an approach to simulate efficiently the acoustic radiation from automotive components. With this aim in mind, the acoustic response of a realistic powertrain unit subjected to working conditions ranging from 1000 RPM to 4500 RPM is studied until 3000 Hz. Several radiating boundary conditions will be assessed in order to detect the most efficient set-up for this kind of problem and to extract the optimized modeling guidelines.
2016-06-15
Technical Paper
2016-01-1792
Aurélien Lonni, Olivier Tanneau
Abstract Nowadays, downsizing and turbochargers are more frequently used, mostly for petrol engines. It can lead to an increase of NVH issues related to the turbos, such as the hiss noise propagation in the air ducts. Hutchinson, among all its activities, supplies rubber and plastic parts for the car industry, especially in fluid management systems. The turbocharger’s airborne noise issue has now been tackled for ten years by implementing acoustic devices in the line and providing solutions to car manufacturers with our hot-side rubber ducts. In this paper, will be first presented the main HP air loop NVH issues, and then explained an approach to design technical solutions. Generally speaking, the noise propagates inside the hot side air hoses, crosses the weakest parts of the system by acoustic emissivity to reach finally the driver and passengers’ ears.
2016-06-15
Technical Paper
2016-01-1793
Sandra Forget, Nicolas Totaro, Jean-Louis Guyader, Michel Schaeffer
Abstract The constant evolution in the automotive sector to achieve more eco-friendly vehicles has induced the development of more efficient systems with new components and innovative materials. To evaluate the impact of these technologies or to improve them in terms of NVH performances, acoustic engineers rely on experimental tests and numerical computations. In this context, the use of experimental noise sources identification and characterization methods can provide interesting approaches. However, classical methods usually used in industry like the Nearfield Acoustical Holography (NAH) or the Beamforming techniques are quickly limited, in particular in terms of precision in localization, for such analysis support. The presented method, named M-iPTF for Mixed inverse Patch Transfer Functions, is more suitable as it is able to localize and quantify all acoustic source fields directly on the real geometry of a complex structure.
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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