Simulation and optimisation of commercial vehicle brake disc based on thermal-structural coupling characteristic

Commercial vehicle brake discs carry enormous thermal energy and load, and their strength and stability have always been of great concern. During braking, the temperature and stress fields of the brake disc interact, embodying thermal-structural coupling characteristic. In this paper, the material properties of grey cast iron and compacted cast iron were tested from 20°C to 1000°C. Grey cast iron has advantages in specific heat capacity, thermal conductivity and coefficient of thermal expansion, while compacted cast iron has advantages in Young’s modulus and strength, at the same temperature. Secondly, an anti-coning disc and a standard disc, were compared in combination with two materials. It was found that the heat transfer coefficient of the anti-coning disc could exceed that of the standard disc for ideal inlet air conditions. Under emergency braking conditions, the maximum temperatures of the anti-coning discs made of grey cast iron and compacted cast iron were reduced by 70.9°C and 87.0°C, respectively, compared to the standard discs of the same material. The crack initiation life of the anti-coning and the standard discs made of grey cast iron were 5.47 times and 1.2 times higher than that of the compacted cast iron discs with the same structure. Finally, the optimisation of the vented channels showed that the use of rhombus and drop shaped ribs increased the crack initiation life by more than 11%, whereas circle shaped ribs had a negative effect.