Temperature field and wear analysis of different brake pad structures of high-speed trains under wheel-rail excitation

Abstract To research the wear behaviors of various brake pad structures during train braking under wheel-rail excitation, the paper constructed a dynamic model of the Simpack high-speed train as a whole and a thermo-mechanical coupled model of the brake disc with different pad structures, based on vehicle-track coupled dynamics theory and the finite element method. By combining the Umeshmotion subroutine with ALE (Arbitrary Lagrangian-Eulerian) adaptive mesh refinement technology, the simulation analysis adopts uniform deceleration conditions, using the train’s starting speed of 80 km h −1 and deceleration during braking of 1.22 m s −2 . Results indicate that during braking, the vertical displacement amplitude range of the brake disc (-0.02 mm to 0.02 mm) exceeds its lateral displacement amplitude range (-0.008 mm to 0.01 mm); both pad structures and wheel-rail excitation influence the brake disc temperature field. Wheel-rail excitation affects the radial peak temperature and peak temperature attainment time by altering the pad-disc contact condition, but it has a negligible impact on the surface average temperature and the inter-configurational difference in radial peak temperature across the three pad types; wheel-rail excitation accelerates brake pad wear: compared with the scenario without wheel-rail excitation, the hexagonal, circular, and triangular pads exhibit increased wear rates of 12.19%, 11.71%, and 5.51%, respectively, with greater wear occurring in the entry zone of the friction area than in the exit zone. The findings clarify the coupled influence of wheel-rail excitation and pad structure on braking wear, providing crucial theoretical foundations and technical references for optimizing high-speed train pad structures, enhancing the reliability of braking systems, and extending their service life.