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Viewing 31 to 60 of 9407
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.
2016-09-18
Journal Article
2016-01-1944
Seongjoo Lee, JeSung Jeon, ShinWook Kim, ShinWan Kim, Seong Rhee, Wan Gyu Lee, Young Sun Cho, Jeongkyu Kim
When two identical brakes are simultaneously tested on a vehicle chassis dynamometer, very often the left hand brake is found to squeal more or less than the right hand brake, all at different frequencies. This study was performed to develop some understanding of this puzzling phenomenon. It is found that as the wear rate difference between the inner pad and the outer pad increases, low frequency (caliper and knuckle) squeals occur more and more, and as the differential wear becomes larger and larger, high frequency (disc) squeals occur less and less, finally disappearing all together. Discs and calipers are found to affect the differential pad wear, in turn affecting brake squeal generation.
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.
2016-09-14
Article
A high-fidelity test bed is used to conduct cyber assurance testing for commercial vehicles including long-haul trucks.
2016-09-14
Article
Exa and Navistar researchers examine CFD simulations and wind-tunnel test results to increase the understanding of simulation methods used to reveal aerodynamic losses in the real-world environment.
2016-09-10
Article
The connected car’s emergence is as disruptive for insurance companies as it is for automakers. Usage based insurance (UBI) holds a major role in future plans, prompting insurers to partner with OEMs and create apps that provide services that make UBI more attractive to customers.
2016-09-10
WIP Standard
AIR1811B
The purpose of this Aerospace Information Report (AIR) is to provide guidelines for the selection and design of airborne liquid cooling systems. This publication is applicable to liquid cooling systems of the closed loop type and the expendable coolant type in which the primary function is transporting of heat from its source to a heat sink. Most liquid cooling system applications are oriented toward the cooling of electronics. Liquid cooling techniques, heat sinks, design features, selection of coolants, corrosion control, and servicing requirements for these systems are presented. Information on vapor compression refrigeration systems, which are a type of cooling system, is found in Reference 1.
2016-09-06
Article
To speed up noise and vibration data analysis for vehicle manufacturers and industrial machinery, Brüel & Kjær offers RT Pro 7.3 enhanced software for its Photon signal analyzer.
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?
2016-08-26
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.
CURRENT
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.
CURRENT
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.
CURRENT
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.
CURRENT
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.
CURRENT
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.
Viewing 31 to 60 of 9407

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