Thermal Structure Coupled Simulation For Air Disc Brake Of Automobile

With the rapid development of auto industry, the auto possession increases by an amazing speed. At the same time, traffic accident is also increasing all the time, the safety of auto is so important that it catches more and more attention of drivers. Brake is the core component of the vehicle brake system, its performance has directly influence on the safety of automobile. From the current market situation, the application of disc brake is more widely used and the trend of replacing the traditional drug brake is unstoppable. Therefore, the study of disc brake has an important significance. Especially, the studying of the air disc brake (ADB) which has large braking torque and used for large load vehicles such as heavy trucks, buses and trailers is extremely valuable.Based on summarizing the researching history course and current situation of temperature and tress field for disc brake, taking one of Wuhan Youfin products as an example, the paper derives the three-dimensional transient temperature field of heat conduction equation of the disc brake system, creates3D model according to its actual size and then establishes the thermal-structural coupled finite element model for braking system. After determining the heat flux boundary conditions and convection conditions, based on the finite element analysis software-ABAQUS, the paper establish the thermal-structure coupled finite element model for braking system which is applied to simulate the emergency brake process of the auto. During the simulation, the movement of the heat resource generated by friction and the coupling of temperature, contact express and equivalent stress are considered, and the change of the heat transfer coefficient is also taken into account. Based on the simulation result of transient temperature field and stress field, if forecasted the thermal fatigue life of the disc brake by using the Manson-Coffin formula, and the affecting factor of life of brake is analyzed.The paper analyzes the distribution of the transient temperature, contact pressure and stress field of the disc during the process of heat fluxing and convective transferring under the condition of time-varying moving thermal load by simulating thermal-structure coupling field for disc brake system. In the process of urgency braking, the temperature of disk shows the non-axisymmetric distribution and takes on significant difference in both tangential and radial directions. As the braking process goes by, the temperature field tends to be the axial symmetric distribution. The highest temperature of disk during the braking process is on the middle segment along the radial direction, and also the biggest stress is on the somewhere of middle segment along the radial direction, all these phenomenon is the action of friction heat and heat convection simultaneously.The analysis method in this article has reference value to the simulation of braking process. The calculating result provides the basis for analyzing the cracks on the disk, and supplied a reference for solution of preventing cracks, it also lay the foundation for the structural optimization of disc brake design.