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For the friction and wear of the braking surface of the disc brake, the mechanism of friction contact deformation of rough surface is analyzed. Considering elastoplastic contact mechanics of the friction surfaces, combined with Archard wear calculation theory, a wear calculation model of fractal rough surface is established, and a wear life prediction of the brake disc is proposed. Based on high-speed and heavy-load braking conditions, the influence of different braking parameters on the surface wear of brake disc is studied. Moreover, a pin-on-disc wear test is used to verify the validity of the wear calculation model, and the average relative error of test and simulation is 4.97%. The research results show that the fractal parameters affect the complexity of the rough surface, and surface wear is mainly caused by interface plastic contact. The friction coefficient is large, which can strengthen the surface shear effect. Large load and high speed would increase the real contact area of the surface and increase the wear volume per unit time. Furthermore, the wear life of the brake disc could be estimated, which is of great significance for raising the wear life of the brake disc, improving braking life and braking efficiency.

The brake disc plays a crucial role to keep the stable braking of a high-speed and heavy-duty disc brake. There is always high temperature, brake vibration, and even serious deformation under braking pressure and frictional resistance. To improve brake performance, this paper aims to find new internal and surface structures of the brake disc. An equivalent moving load (EML) topology optimization method for internal structure is proposed. Topography optimization method oriented to displacement and stress control for surface structure is carried out. Multiobjective functions containing thermal-structural coupled rigidity and natural frequency of the brake disc are established in the internal and surface structure optimizations. Internal and surface structures of the brake disc are optimized, and the mechanic properties of the brake disc are improved. Thermal-structural coupling and modal analyses are verified with high-speed and heavy-duty brake working conditions. The results show that new brake disc structures meet the requirements, and the effectiveness of the proposed EML topology optimization and topography optimization methods has been proved.

In view of the braking process for the megawatt wind turbine brakes, considering the geometric and motion characteristics of brake pads and brake discs, a displacement gradient circulation method is put forward in this article, to resolve the deviation of coupling results caused by the difference of friction effect along the radial/circumferential direction of brake disc, and the thermal–structural coupling analysis of friction pair during the braking process is carried out. A three-dimensional model of transient heat transfer for brake friction pair is built based on the Abaqus software. The heat flow density is loaded by the displacement gradient circulation method, which is used to calculate the frictional heat flow during the braking process. The analysis results show that along the circumferential direction of the brake disc the temperature distribution in the friction zone is non-uniform and the temperature starting from the contact position of the brake disc and the brake pad decreases along the counterclockwise direction. The thermal stress caused by the temperature field during the braking process is the main factor causing the brake disc/pad failure. The effectiveness of the method and the model is verified by the designed inertia braking experiments. The analytical method proposed in this article provides a reference for simulating the friction braking process of large-size disc brakes.