Thermal-structure Conpling Analysis And Vibration Modal Analysis Of Disc Brake

The vehicle brake system is extremely important part. It is directly related to the safety of drivers and passengers. Because of the disc brake’s stable performance, simple structure and fast heat dissipation, it has been widely used in automobile. Thermal-structure coupling effect of the brake in the process of the brake impact on the brake noise, vibration and thermal fatigue. Thus, it affects the braking effect. So the thermal structure coupling analysis of the disc brake is very important.This thesis analyzes the simulation coupled thermal and structural under emergency braking condition of a disc brake, and thermal fatigue life of brake in the braking conditions predicted by Manson-Coffin formula. At last, the brake mode was studied. The main research work is as follows:(1) Through the CAD drawings of a disc brake, a simplified three dimensional model is estabished, the thermal boundary conditions and mechanical boundary conditions are calculated, based on Thermal-structure coupling Theory, provide the basis for subsequent analysis.(2) Through establishing the finite element model in the application of finite element software ABAQUS and simulating the process of thermal-structure coupling in the condition of emergency braking, obtain the distribution of temperature field, stress field and contact stress field. Shown by simulation results, in emergency braking condition, the temperature field and stress field of brake disc are non-axisymmetric distribution, and high temperature and high stress areas are located in the friction radius. With the braking process, the temperature field and stress field of brake disc will slowly become nearly axisymmetric distribution. For the friction piece, the maximum contact pressure is at the middle part and the entrance area of friction. However the high temperature is mainly distributed near the friction area in the middle part of the outlet.(3) Based on the simulation of thermal structure coupling, determine the most prone to crack in the brake discs, predict the thermal fatigue life of brake in the braking condition using the Manson-Coffin formula.(4) the vibration modal of disc brake was studied, through extracting and analyzing the first ten order modal extraction of brake disc and the friction plate, find that the modal frequencies are overlapping. It may cause resonance, result in bad friction contact between the friction pairs and impact on the braking effect. The brake disc structure was improved through increasing convex structure at its edges. The results show that the modal frequency of brake disc and the friction plate differ considerably, achieving the objective of avoiding the resonance.In this thesis, the results provide a theoretical reference for the design improvement and materials selection of brake.