Orthogonalanisostopic C/SiC Composite Ventilated Disc Brake Vibration Modaland Thermai-Mechanical Coupling Simulation Optimization Analysis

The brake plays a vital role in the safety of a vehicle on the road.In the process of driving,the brake can allow the car to slow down or stop quickly when necessary,so as to avoid traffic accidents caused by poor braking.At the same time,the brake also improves the handling performance of the car,which is convenient for the driver to control the car in an emergency and ensure driving safety.When the brake vibrates and frictions,it will emit noise and heat,leading to excessive temperatures and thermal stress,which may have a potential impact on the safety of the brake.Therefore,accurate vibration stability and thermal-mechanical coupling simulation analysis of the brake can provide a deeper understanding of the thermodynamic performance of the brake and further improve the braking efficiency and safety.In this paper,the orthotropic anisotropic C/SiC composite automotive ventilated disc brake was the main research object.Firstly,a three-dimensional finite element model was established according to the actual size of the automobile brake.Based on the complex modal simulation analysis theory,a complex eigenvalue modal analysis was conducted based on the finite element software ABAQUS for the orthotropic anisotropic C/SiC composite automotive ventilated disc brake by dividing the grid,setting the relevant parameters and applying the boundary conditions.The characteristic values and mode shapes were extracted,and the influence factors of the vibration modes were analyzed from the structural parameters,material parameters and working conditions parameters.Based on the theoretical basis of thermal-mechanical coupling simulation,the braking conditions,thermal load boundary and displacement boundary conditions of the ventilated disc brake were calculated and determined,and the grid was divided,the relevant parameters were set and boundary conditions were applied in the nonlinear finite element software ABAQUS.Using the finite element software ABAQUS,the thermal-mechanical coupling simulation was carried out for the gray cast iron material brake,C/SiC composite material brake and aluminum alloy composite material brake,and the distribution characteristics of the temperature field and stress field of the brake discs were compared respectively.Through the complete thermal-mechanical coupling method,the simulation of the orthotropic C/SiC composite brake under the emergency braking condition was carried out,and the temperature and stress variation trends of the radial,axial and circumferential nodes were explored.The distribution nephogram and distribution law of transient temperature field and stress field of orthotropic C/SiC composite brake disc in the process of emergency braking were summarized,and the coupling relationship between them was explored.Finally,based on the established orthotropic anisotropic C/SiC composite brake,the three-dimensional brake models of circular pit structure and square pit structure were established,and the four aspects of depth,diameter,circumferential interval of adjacent pits and type of pits were optimized by orthogonal test,and the brake structure with good heat dissipation was obtained.Based on the results of simulation optimization,considering different initial braking speed,braking pressure,friction coefficient,expansion coefficient and other influencing factors,the temperature field of the optimized model was analyzed.