The Transient Thermal Stress and Deflection of a Brake

This study utilizes the finite element method with a two-dimensional model of a disk brake and investigates its distributions of the transient temperature, thermal gradient, heat flux, thermal stress and deflection due to friction. A specified initial uniform temperature of the disk is used to simulate heat transfer of the disk. Since the temperature of the disk brake inboard is higher than that of the disk brake outboard, the deflection of the disk brake inboard is larger than those at other locations. The maximum deflection of 0.4 mm occurs at the outer diameter of the disk inboard. The disk expands radial outward and bends from the disk brake inboard toward the disk brake outboard. The coning angle between the disk outboard surface and the original vertical disk outboard surface is 0.39°, which is comparable with the existing datum of 0.35°. The principal stresses at the lower mounting location are 184 MPa and 236 MPa. The calculated safety factor is 1.27 based on the modified Mohr theory used for brittle materials, and this disk brake is reliable.