Multi-scale Simulation Of Brake Disc/Pad Wear Of High-Power Disc Brake

When the high-power disc brake is used for emergency braking under heavy-load and high-speed conditions,thermal wear of the brake interface could occur due to a large amount of frictional heat.Hard particles scratch the brake interface to cause abrasive wear,which causes the brake braking performance to decrease.Therefore,studying the wear phenomenon and regularity of the high-power disc brake during the braking process is of great significance for improving the braking efficiency of the brake system.In this paper,the wear of the brake disc/pad of the high-power disc brake is taken as the research object.The multi-scale analysis method is used to study the wear process and wear law of the brake interface.The main research contents are as follows:(1)Based on the characteristics of high-speed and heavy-load braking conditions,the calculation formula of Archard abrasive wear was improved by using the micro-element method.The wear calculation model was established.At the macro-scale,the braking process of the brake pad was carried out by using finite element method.The wear distribution of the brake pad surface was analyzed.The wear law of the brake pad was explored and verified by the actual experiment.The results show that the wear of the friction inlet position of the brake pad is relatively large.The increasing of the braking load and the initial braking speed could aggravate the wear of the brake pad.(2)Considering the motion characteristics of the brake disc,the wear calculation model for the brake disc of the disc brake was derived.The wear law of the brake disc surface was analyzed by finite element method.The variation curves of the wear depth of the brake disc during the braking process at the macro-scale was obtained.The availability of the finite element wear model was verified by the pin-disc test.The influence of the braking parameters on the brake disc wear was studied by the control variable method.The results show that the braking load increases the actual contact area of the brake interface,resulting in the increase of wear.The increase of the initial braking speed makes the wear severe by the increase degree of shear damage of the material.(3)The finite element-discrete element coupling method was used,the wear model of the brake disc/pad brake interface at the meso-scale was established.The form of the material shedding and the distribution between the particles of the brake interface were analyzed.The wear law of the brake interface at the meso-scale was obtained.The discrete element simulation results and finite element simulation results were compared and analyzed,and the feasibility of the discrete element model was verified.The results show that the brake pad wear is significantly more serious than the brake disc.The increase of braking load and the initial braking speed tend to break the parallel bond between the particles,causing severe material damage and accelerating the wear of the brake interface.In this study,the wear laws of the brake disc and brake pad of high-power disc brake at macro-scale and meso-scale are studied respectively,and the influence of braking parameters on the wear of the brake interface is investigated.It provides a theoretical basis for the design of brake disc and brake pad,and provides technical support for the improvement of brake wear life.