Dynamic Analysis of Dry Frictional Disc Brake System Based on the Rigid-Flexible Coupled Model

A rigid-flexible coupled dynamic model is established to investigate the dynamic behaviors of a disc brake system. The analytical model of the pad includes transverse and circumferential displacements. The disc is modeled using the thin plate theory. A governing equation of the motion of the disc is established. Then the first-order vibration equation is obtained using Galerkin method, considering only the transverse displacement. The friction between the pad and disk among the contacting area is estimated using an exponential model, in which the Stribeck effect is included. Numerical method is applied to reveal the influences of coupling dynamical relationships between the pad and disc on the whole system. The results show that with the variation of disc annular speed, the pad keeps vibrating with small amplitude due to the sustaining variation of the contacting pressure and friction. Stick-slip flutter happens as the velocity is lower than a critical speed and strong movement coupling between elements of the system brings earlier occurrence of the frictional flutter. Besides, for strong movement coupling case, before the critical speed, there are intermittent frequency ranges among which the amplitude is quite higher, which is due to a redistribution of friction and contacting pressure.