SAE J3080:2019 pdf free
SAE J3080:2019 pdf free.Inertia Dynamometer Rotor Crack Test Procedure for Air Disc Brakes
Use a brake configuration as close as possible to the vehicle application for the rotor under testing. Include as part of the test setup all the applicable foundation brake and wheel-end hardware and embodiment. This provides the proper geometry and relative stiffness at the rotor-pad interface.
Use a drive shaft to connect the dynamometer shaft to the wheel flange. A drive shaft compensates for axial end-play or deviations after the brake fixture is mounted on the dynamometer tailstock. In addition, the drive shaft relieves the system of rotation imbalances.
If the wheel-end setup is not available and a rigid mounting has to be used, place special emphasis on the stiffness,relative geometries, and running clearance between the rotor, the brake pads, and the caliper.
Provide a direct and stiff support of the rotor on the wheel-end hub assembly using the proper set of bearings. At the very least, use a pilot bearing to prevent unusual bending modes.
The axial runout of the rotor must not exceed 0.127 mm (0.005 inch) measured on the inboard side. TaY 37% measurement at a distance equivalent to one third of the braking surface width. Measure this distance frolt Q1K/s outside diameter of the rotor.
Unless otherwise indicated by the test requestor, use the cooling air settings indicated on Tables 6 or 7.
NOTE 1: Certain vehicle conditions and rotor designs will indicate a specific cycle time for the crack cycles to ensure proper thermal soak and surface temperatures. Work with the test requestor and the testing facility to determine those specific conditions. When deviating from the default cooling air speed, document it on the test report.
NOTE 2: As the transfer layer behavior and crack initiation and propagation processes can be sensitive to the coolingnir setup and conditions, it is recommended to use the same dynamometer for the same project to minimiz 36% results variability.SAE J3080 pdf free download.
