Study on the service behavior of rivets connected with brake pads of high speed trains

The connecting rivets of the brake pads may undergo fatigue failure during braking, causing the friction plates to detach and thereby endangering the safety of train operation. This paper combines the interference matching riveting theory and the finite element analysis method to conduct a simulation analysis of the riveting process of the brake pads. Furthermore, considering the coupling effects such as residual compressive stress, temperature and mechanical stress during the forming of the rivets, a thermal-mechanical coupling analysis model for the brake pads of high-speed trains is established. Through the 1:1 high-speed train braking test bench, the temperature of the brake disc was compared and analyzed with the simulation results, with an error of 9.22%. This verified the rationality of the model. The variation patterns and causes of the contact stress, temperature field and displacement of the rivets under different initial braking speeds were studied. The results show that the contact stress values of the rivets at the inlet and outlet of the brake pads are relatively high. The displacement fluctuation range of the rivets increases with the increase of braking speed, and the temperature rise of the rivets also increases with the increase of the displacement fluctuation range of the rivets. As the braking speed increases, the displacement fluctuation range of the rivet along the axis direction expands by 85 μm, the temperature rises by 9.5 ℃, and the contact stress increases by 20.2 MPa. The service results of the rivet provide a basis for the failure study of the rivet.