Display:

Results

Viewing 61 to 90 of 10698
2016-09-18
Journal Article
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 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
2016-01-1943
Tadayoshi Matsumori, Yoshitsugu Goto, Noboru Sugiura, Kenji Abe, Yoshihiro Osawa, Yosuke Akita, Satoshi Wakamatsu, Katsuya Okayama, Kyoko Kosaka
This paper deals with friction under wet condition in the disk brake system of automobiles. In our previous study, the variation of friction coefficient μ was observed under wet condition. And it was experimentally found that μ becomes high when wear debris contains little moisture. Based on the result, in this paper, we propose a hypothesis that agglomerates composed of the wet wear debris induce the μ variation as the agglomerates are jammed in the gaps between the friction surfaces of a brake pad and a disk rotor. For supporting the hypothesis, firstly, we measure the friction property of the wet wear debris, and confirm that the capillary force under the pendular state is a factor contributing to the μ variation. After that, we simulate the wear debris behavior with or without the capillary force using the particle-based simulation. We prepare the simulation model for the friction surfaces which contribute to the friction force through the wear debris.
2016-09-18
Journal Article
2016-01-1949
John David Fieldhouse, Joe Gelb
The design of a braking system involves a delicate balance between the friction pair, the disc and pad, where the pad is a complex blend of constituents to provide predictable characteristics, typically, a known and consistent friction level. In its base form the brake has to absorb the vehicle kinetic energy by converting it into heat. This heat absorption by the friction pair can result in chemical and physical interactions with the release of debris about which we know little. Other than environmental concerns, brake dust causes unnecessary problems with wear, thermal gradients (hot banding) and NVH. This paper is concerned with the removal and collection of brake debris from the friction interface - the debris being regarded as solids and airborne particles, the latter less than 10μm in size. The test procedure consisted of a Burnish program followed by 8 different drive cycles. The overall effects of debris removal is then reported for each test.
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
2016-01-1958
Seungpyo Lee, Nahyon Lee, Jongkeun Lim, Jungyang Park
Through transmitting power and carrying vehicle weight, automotive wheel bearings play an important role. Counterbalancing the bearing responsibilities, they also are designed to last the life of a vehicle without servicing. When mounted to the vehicle steering knuckle by bolts, distortion occurs to the outer ring. Performance is affected when distortion takes place at the seal mounting location and raceways. Finite element analysis using commercial software was performed to analyze the outer ring distortion. Elasto-plastic and contact analyses were carried out to compute the clamping behavior of the outer ring, bolts and the knuckle under various conditions. To verify the reliability of this study, the distortion of the outer ring was measured. The experimental results proved to be comparative with the analysis results.
2016-09-18
Journal Article
2016-01-1959
Laura Sguotti, Davide Olivieri, Domenico Bosco
Bearing friction is a direct contribution to vehicle CO2 emissions. The friction is defined as the total resistance to rotation, resulting from the combination of rolling and sliding friction in the contact areas. First, friction reduction was approached from a theoretical standpoint by employing modeling and simulation techniques. Improvements identified in simulation were then used to: create a new set of design rules for the internal geometry of the bearing, introduce a new grease, develop new seals, also with the integration of labyrinth functions and an optimization of the preload range variation. In order to provide a reliable confirmation of the expected achievements, a new friction measurement methodology was also introduced.
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
Journal Article
2016-01-1911
Philippe Dufrenoy, Vincent Magnier, Yassine WADDAD, Jean-Francois Brunel, Gery DE SAXCE
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
2016-01-1910
Philippe Dufrenoy, Vincent Magnier, Ruddy MANN, Anne-Lise CRISTOL, ITZIAR SERRANO
A methodology to identify the bulk properties of friction material from their formulation V. Magnier; I. Serrano; AL. Cristol ; P. Dufrénoy* University of Lille Cité scientifique Avenue Paul Langevin F-59655 Villeneuve d’Ascq Cedex * Corresponding author : philippe.dufrenoy@univ-lille1.fr Friction materials for braking applications are made of a high number of components leading to bulk properties which guarantee the performances. Development are mainly made by a trial-error methodology due to the misunderstanding of the relationship between formulation and process and properties. In this work we propose to identify this relationship by an experimental methodology combined with microstructural analysis. The first step is the description of the microstructure obtained by tomographic analysis leading to quantitative information about the morphology of the components, their distribution in the volume, orientations, etc.
2016-09-18
Technical Paper
2016-01-1920
Deaglan O'Meachair, Stamatis Angelinas, Matthew Crumpton, Antonio Rubio Flores, Juan Garcia, Pablo Barles
Bentley Motors Ltd. has developed a Carbon Silicon Carbide (CSiC) brake system for it’s Mulsanne product, introduced at 17MY. The CSiC brake system is conceived as a performance brake system, and as such offers notable improvements in brake performance In developing the brake system, particular focus was placed on meeting the refinement levels required for a premium product, and indeed as the flagship model for Bentley Motors, NVH refinement of the brake system was of particular concern. This paper intends to discuss the technical performance of the brake system and review the NVH performance of the brakes. This paper will also demonstrate the effect of vehicle isolation on the cabin NVH, and ultimately the passenger experience, by comparing the noise and vibration content in the wheel arch with that apparent to the driver.
2016-09-16
Journal Article
2016-01-9018
Judhajit Roy, E. Harry Law
Abstract It is well known that the ride quality of trucks is much harsher than that of automobiles. Additionally, truck drivers typically drive trucks for much longer duration than automobile drivers. These two factors contribute to the fatigue that a truck driver typically experiences during long haul deliveries. Fatigue reduces driver alertness and increases reaction times, increasing the possibility of an accident. One may conclude that better ride quality contributes to safer operation. The secondary suspensions of a tractor have been an area of particular interest because of the considerable ride comfort improvements they provide. A gap exists in the current engineering domain of an easily configurable high fidelity low computational cost simulation tool to analyze the ride of a tractor semi-trailer. For a preliminary design study, a 15 d.o.f. model of the tractor semi-trailer was developed to simulate in the Matlab/Simulink environment.
2016-09-14
Technical Paper
2016-01-1872
Bin Wu, Xichan Zhu, Lin li
Abstract Based on the emergency lane change cases extracted from the China naturalistic driving data, the driving steering behavior divides into three phases: collision avoidance, lateral movement and steering stabilization. Using the steering primitive fitting by Gaussian function, the distribution of the duration time, the relationship between steering wheel rate and deflection were analyzed in three phases. It is shown that the steering behavior essentially is composed of steering primitives during the emergency lane-change. However, the combination of the steering primitives is different according to the specific steering constraints in three phases. In the collision avoidance phase, a single steering primitive with high peak is used for the fast steering; in the lateral movement and stabilization phase, a combination of two or even more steering primitives is built to a more accurate steering.
2016-09-14
Technical Paper
2016-01-1871
Renxie Zhang
Abstract Path following controller of a six-wheel skid-steering vehicle is designed. The vehicle speed is controlled through engine speed control and the lateral vehicle steering is controlled through hydraulic braking on each side. Contrary to the common approaches considering non-holonomic constraints, vehicle dynamic characteristics and nonlinear characteristics of tire are considered. A hierarchical control structure is applied in this vehicle control system. The kinematic controller works out the reference yaw rate and reference vehicle speed. And a robust dynamic controller tracks the reference signal. In addition, the dynamic controller takes actuator ability into account.
2016-09-14
Technical Paper
2016-01-1886
Zhuoping Yu, Yi Zhang, Lu Xiong, Songyun Xu
Abstract With development of vehicle advanced driver assistant system and intelligent techniques, safer and more intelligent Integrated-Electro-Hydraulic Braking System is required to realize brake-by-wire. Thus, more and more companies and universities developed Integrated-Electro-Hydraulic Braking System to fulfill these requirements. In this paper, an Integrated-Electro-Hydraulic Braking System is introduced, which consists of active source power, pedal feel emulator and electro control unit. As a composite system of mechanic, electron and hydraulic pressure, the Integrated-Electro-Hydraulic Braking System has complex system characteristics. Integrated-Electro-Hydraulic Braking System and active power source have very different dynamic characteristics. So algorithms of hydraulic pressure control and motor control should be apart, but algorithm of them should be united in hardware to meet integration demand.
2016-09-14
Technical Paper
2016-01-1902
Xiaoyu Wang, Yun Zhao, Yufeng Lian, Yantao Tian
Abstract A new lateral stability control method, which is based on vehicle sideslip angle and tire cornering stiffness estimation, is proposed to improve the lateral stability of the four-in-wheel-motor-driven electric vehicle (FIWMD-EV) in this paper. Through the lateral tire force information, vehicle sideslip angle can be estimated by the extended kalman filter (EKF). Using the estimated vehicle sideslip angle, tire cornering stiffness can be also estimated by forgetting factor recursive least squares (FFRLS). Furthermore, combining with the vehicle dynamics model, an adaptive control target model is proposed with the information on vehicle sideslip angle and tire cornering stiffness. The new lateral stability control system uses the direct yaw moment control (DYC) based on dynamic sliding mode is proposed. The performance and effectiveness of the proposed vehicle state estimation and lateral stability control system are verified by CarSim and Simulink cosimulation.
2016-09-14
Technical Paper
2016-01-1905
Gaoming Fang, Hui Chen
Abstract Electric Power Steering (EPS) is the actuator of several lateral-dynamic-related Advanced Driver Assistance Systems (ADAS). A driving simulator with EPS will be much helpful for the ADAS development. However, if a real EPS is used in the driving simulator, it is quite difficult to realize the road reaction force accurately and responsively. To overcome this weakness, a virtual EPS platform is established. The virtual EPS platform contains two parts: one is the vehicle and EPS model, the other is the force feedback actuator (FFA) of the Steer-by-Wire (SBW) system. The FFA is an interface between the driver and the EPS/vehicle model. The reactive torque of the FFA is obtained based on the models. Meanwhile, the input of the EPS model is the steering angle of the FFA. Comparing to a real EPS, the virtual EPS platform has a problem of instability because of the actuator lag of the FFA. Therefore, a damping control method is applied to make the system stable.
2016-08-23
Article
The all-new Armor Max Pro Grade MSD tire from Goodyear builds on the toughness of the Goodyear G177, while providing enhanced traction, miles to removal and retread ability.
2016-08-17
WIP Standard
J1401

This SAE Standard specifies the performance tests and requirements for hydraulic brake hose assemblies used in the hydraulic braking system of a road vehicle. It also specifies the methods used for identification of the hose manufacturer.

This document applies to brake hose assemblies made of a hose fabricated from yarn and natural or synthetic elastomers and assembled with metal end fittings for use with nonpetroleum-base brake fluids as specified in SAE J1703, SAE J1704 and SAE J1705.

The nominal internal diameter of the brake hose shall fall within one of the following values:

    a. less than 4 mm (1/8 in or less)
    b. 4 to 5 mm (3/16 in)

2016-08-16
Standard
J1615_201608
Male pipe threads, including male dryseal pipe threads, when made into assemblies or installed into ports, will generally leak if not covered with a sealant. This SAE Recommended Practice is intended as a guide to assist designers and/or users in the selection and application of various types of thread sealants. The designers and users must make a systematic review of each type and application and then select the sealant to fulfill the requirements of the application. The following are general guidelines and are not necessarily a complete list.
2016-08-11
Standard
AS24586B
SCOPE IS UNAVAILABLE.
2016-08-09
Standard
J45_201608
This SAE Recommended Practice establishes a uniform procedure for the level surface testing of hand-operated brake systems on recreational noncompetitive snowmobiles.
2016-08-05
Magazine
Clearing the air Sensors, diagnostics and controls advance to help trap emissions. Bringing the heat on cooling technologies Electronic controls, variable-speed fans cool engines, heat aftertreatment systems. 3D printing machines can't be built fast enough In the additive manufacturing world, the costs of components are dropping, the technology is becoming more reliable and parts are fabricated faster, allowing industries beyond aerospace to adopt additive technologies, says Oak Ridge Lab's Ryan Dehoff.
2016-08-02
Standard
J1121_201608
This recommended practice has been developed to assist engineers and designers in the preparation of specifications for the major types of helical compression and extension springs. It is restricted to a concise presentation of items which will promote an adequate understanding between spring manufacturer and spring user of the major practical requirements in the finished spring. Closer tolerances are obtainable where greater accuracy is required and the increased cost is justified. For the basic concepts underlying the spring design and for many of the details see the SAE Information Report MANUAL ON DESIGN AND APPLICATION OF HELICAL AND SPIRAL SPRINGS, SAE HS 795, which is available from SAE Headquarters in Warrendale, PA 15096. A uniform method for specifying design information is shown in the TYPICAL DESIGN CHECK LISTS FOR HELICAL SPRINGS, SAE J1122.
2016-08-02
Standard
J1122_201608
This SAE Recommended Practice furnishes sample forms for helical compression, extension and torsion springs to provide a uniform method for specifying design information. It is not necessary to fill in all the data, but sufficient information must be supplied to fully describe the part and to satisfy the requirements of its application. For detailed information, see 'Design and Application of Helical and Spiral Springs - SAE HS 795 SEP82', also 'Helical Compression and Extension Spring Terminology - SAE J1121 NOV75.' Both of these documents use SI (metric) units in accordance with the provisions of SAE J916 MAY85, and so does SAE J1122. Here, however, the U.S. Customary Units (in, lb, psi) have been added in parentheses after each SI Unit for the convenience of the user who must furnish specifications on a project where all requirements are listed in non-metric terms.
2016-08-01
Article
For 2016, the fourth year of its annual Enlighten Awards that acknowledge the best innovations in vehicle weight reduction, Altair named GM’s 2016 Cadillac CT6 as the winner in the Full-Vehicle category and ContiTech’s polyamide rear-axle transmission crossbeam is the winner in the Enlighten Awards’ Module category.
2016-07-27
Standard
J1802/1_201607
This SAE Recommended Practice contains the reference information for SAE J1802.
2016-07-20
Standard
J1409_201607
This SAE Recommended Practice establishes uniform test procedures for air brake systems pneumatic valves with respect to: a. Input-Output Performance b. Leakage Characteristics c. Low Temperature Evaluation d. Elevated Temperature Evaluation e. Corrosion Resistance Evaluation f. Endurance Testing g. Structural Integrity h. Vibration Testing
2016-07-20
Standard
J1410_201607
This SAE Recommended Practice establishes minimum performance requirements for new pneumatic valves when tested in accordance with the test procedure outlined in SAE J1409. The performance requirements will include: a. Input-output performance b. Leakage characteristics c. Low temperature performance d. Elevated temperature performance e. Corrosion resistance performance f. Endurance testing g. Structural integrity
2016-07-18
Standard
AS24585C
SCOPE IS UNAVAILABLE.
2016-07-14
Standard
J3079/2_201607
This SAE Standard specifies a method for measuring the deflection of friction materials, noise insulators, and disc brake pad assemblies to be used in road vehicles with a Gross Vehicle Weight Rating below 4336 kg. This part of the SAE J3079 includes the test for deflection and creep at various pressures under ambient temperature conditions. This SAE test method differs from SAE J2468 and ISO 6310 in the preload and maximum load applied to the test sample when deflection is measured. It also introduces additional measurements such as for deflection offset, hysteresis, and creep.
Viewing 61 to 90 of 10698

Filter