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Journal Article

On the Coupling Stiffness in Closed-Loop Coupling Disc Brake Model through Optimization

2015-04-14
2015-01-0668
The study and prevention of unstable vibration is a challenging task for vehicle industry. Improving predicting accuracy of braking squeal model is of great concern. Closed-loop coupling disc brake model is widely used in complex eigenvalue analysis and further analysis. The coupling stiffness of disc rotor and pads is one of the most important parameters in the model. But in most studies the stiffness is calculated by simple static force-deformation simulation. In this paper, a closed-loop coupling disc brake model is built. Initial values of coupling stiffness are estimated from static calculation. Experiment modal analysis of stationary disc brake system with brake line pressure and brake torques applied is conducted. Then an optimization process is initiated to minimize the differences between modal frequencies predicted by the stationary model and those from test. Thus model parameters more close to reality are found.
Standard

Recommended Test Procedure for Powered Gas Brake Control Systems

2007-10-22
HISTORICAL
J2604_200710
This test procedure is for qualification testing of powered gas/brake control systems to assure compliance with the Recommended Practices for these assistive devices. A powered gas/brake control system which passes all of the tests shall be considered to be in compliance with the Recommended Practices. The control shall pass all tests denoted by a “shall” in the Recommended Practice or the Recommended Test Procedure. All the results of all tests and requirements denoted by a “should” shall be noted, but failure to comply will not constitute failure to pass the test.
Standard

Recommended Test Procedure for Powered Gas Brake Control Systems

2021-11-03
CURRENT
J2604_202111
This test procedure is for qualification testing of powered gas/brake control systems to assure compliance with the recommended practices for these assistive devices. A powered gas/brake control system which passes all of the tests shall be considered to be in compliance with the recommended practices. The control shall pass all tests denoted by a “shall” in the recommended practice or the recommended test procedure (RTP). All the results of all tests and requirements denoted by a “should” shall be noted, but failure to comply will not constitute failure to pass the test.
Standard

Validation of Compressibility Test Systems for Friction Materials

2021-01-13
CURRENT
J3079/1_202101
This SAE Recommended Practice (RP) applies to the validation process for test systems used to measure deflection (compressibility, creep, or swell and growth) of friction materials and friction material assemblies. The materials or assemblies can fit passenger cars, light trucks, and commercial vehicles equipped with hydraulic or air brake systems, using disc or drum brakes.
Standard

Low-preload Deflection Measurement for Brake Pads, Noise Shims, and Brake Pad Assemblies

2019-11-22
WIP
J3079/2

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.

Standard

Low-preload Deflection Measurement for Brake Pads, Noise Shims, and Brake Pad Assemblies

2016-07-14
CURRENT
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.
Technical Paper

Integrated Active Safety System for Motor Graders

2021-09-22
2021-26-0137
Safety of the operators in any equipment can be achieved by both passive and active systems. Passive safety system includes Seat belt, air bag, bumper, and other structural components which protects the operator from injuries during accidents. On the other hand, Active safety systems like Braking, Steering, Collision avoidance system, operator fatigue monitoring systems, etc., minimize and eliminate the accidents among which the Brake system is primarily used to control and stop the equipment. Considering the field operating conditions of motor grader, it is very essential to provide fool proof braking system to control and stop the equipment. In order to obtain maximum productivity the equipment speed is kept substantially high. Brake systems are operated using Air, Hydraulics, etc., among which the Air brake system offers simple and easy serviceability over hydraulic system.
Journal Article

Brake Dynamometer Test Variability Part 2- Description of the Influencing Factors

2011-09-18
2011-01-2374
The ISO TC22/SWG2 - Brake Lining Committee established a task force to determine and analyze root causes for variability during dynamometer brake performance testing. SAE paper 2010-01-1697 “Brake Dynamometer Test Variability - Analysis of Root Causes” [1] presents the findings from the phases 1 and 2 of the “Test Variability Project.” The task force was created to address the issue of test variability and to establish possible ways to improve test-to-test and lab-to-lab correlation. This paper presents the findings from phase 3 of this effort-description of factors influencing test variability based on DOE study. This phase concentrated on both qualitative and quantitative description of the factors influencing friction coefficient measurements during dynamometer testing.
Journal Article

Vehicle Integration Factors Affecting Brake Caliper Drag

2012-09-17
2012-01-1830
Disc brakes operate with very close proximity of the brake pads and the brake rotor, with as little as a tenth of a millimeter of movement of the pads required to bring them into full contact with the rotor to generate braking torque. It is usual for a disc brake to operate with some amount of residual drag in the fully released state, signifying constant contact between the pads and the rotor. With this contact, every miniscule movement of the rotor pushes against the brake pads and changes the forces between them. Sustained loads on the brake corner, and maneuvers such as cornering, can both produce rotor movement relative to the caliper, which can push it steadily against one or both of the brake pads. This can greatly increase the residual force in the caliper, and increase drag. This dependence of drag behavior on the movement of the brake rotor creates some vehicle-dependent behavior.
Journal Article

Regenerative Braking Control Enhancement for the Power Split Hybrid Architecture with the Utilization of Hardware-in-the-loop Simulations

2013-04-08
2013-01-1466
This study presents the utilization of the hardware-in-the-loop (HIL) approach for regenerative braking (regen) control enhancement efforts for the power split hybrid vehicle architecture. The HIL stand used in this study includes a production brake control module along with the hydraulic brake system, constituted of an accelerator/brake pedal assembly, electric vacuum booster and pump, brake hydraulic circuit and four brake calipers. This work presents the validation of this HIL simulator with real vehicle data, during mild and heavy braking. Then by using the HIL approach, regen control is enhanced, specifically for two cases. The first case is the jerk in deceleration caused by the brake booster delay, during transitions from regen to friction braking. As an example, the case where the regen is ramped out at a low speed threshold, and the hydraulic braking ramped in, can be considered.
Technical Paper

Topology Optimisation of Brake Caliper

2020-10-05
2020-01-1620
The objective of the research is to develop a lightweight yet stiff, 2 piston fixed brake caliper which can be used in formula student race car. To make a race car, its components need to be lighter. To stop a car with minimum stopping distance, it needs to have a sophisticated braking system with well-designed components. The designing of the caliper is carried out on the Altair Inspire software. The topology optimisation algorithm is used to minimise the weight of the caliper without compromising the stiffness. The structural analysis is also carried out on the Altair Inspire. The caliper is also tested for fatigue failure using Ansys.
Technical Paper

Comparison of Particulate Matter and Number Emissions from a Floating and a Fixed Caliper Brake System of the Same Lining Formulation

2020-10-05
2020-01-1633
The particulate emissions of two brake systems were characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust PN regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a section (trip-10) novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of trip-10 tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle.
Technical Paper

Accelerated Corrosion Tests and the Evaluation of New Automotive Brake Line Coatings

1991-10-01
912292
New corrosion resistant coatings for brake tubing have been evaluated by use of the accelerated vehicle corrosion test and the trailer corrosion test. These tests appear useful for comparing the end point perforation resistance of the tubing coating combination and for comparing the corrosion and paint adhesion properties of the coatings, respectively. The paper discusses the procedure and results of the accelerated vehicle corrosion test as well as burst pressure tests after accelerated vehicle corrosion testing.
Standard

Air Disc Brake Actuator Test Procedure, Truck-Tractor, Bus and Trailer

2020-12-07
CURRENT
J2902_202012
This SAE recommended practice provides procedures and methods for testing service, spring applied parking and combination brake actuators for air disc brake applications. Methods and recommended samples for testing durability, function and environmental performance are listed in 1.1 and 1.2.
Standard

Air Disc Brake Actuator Test Procedure, Truck-Tractor, Bus and Trailer

2014-10-01
HISTORICAL
J2902_201410
This SAE recommended practice provides procedures and methods for testing service, spring applied parking and combination brake actuators for air disc brake applications. Methods and recommended samples for testing durability, function and environmental performance are listed in 1.1 and 1.2.
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