Abstract: According to the real dimension of the braking disc and the pads, the modeling for three-dimensional transient thermal-structure coupling during the emergency braking is established based on the effect of the moving heat source with relative sliding variation and the coupling of the frictional thermal flow between the disc and the pad. By using the nonlinear multiphysics field of the ANSYS software, the braking process of the disc brake is simulated. The distribution of the temperature and the stress of the disc during the braking are analyzed. The temperature and the stress are coupled. During the braking, the transient temperature/stress variation present periodical fluctuations due to the entering heat flux and the thermal convection alternately. The variational period of the temperature/stress increases with the braking time prolonged. And the reason of radial thermal fatigue fracture of the disc is discussed.

Key words: Disc brakes, Numerical modeling, Thermal fatigue fracture, Thermal-structure coupling