Research On Modal And Thermal Analysis Of An Automobile Brake Disc

With the development of time,the function of automobile becomes more and more mature,and people pay more and more attention to the safety of automobile.According to statistics,in a series of traffic accidents,nearly 45% of the time is caused by the failure of the braking system,which is usually caused by the continuous thermal impact of the braking disc.When the car brakes,the speed of the brake disc is close to its natural frequency,the braking system is prone to resonance,noise,harm the safety of the car.Therefore,it is necessary to conduct modal and thermal analysis of the brake disc.In this paper,aiming at the phenomenon of vibration,noise and overheating in the braking process of a certain automobile disc brake,the brake disc is used as the research carrier,and the modal and thermal analysis are carried out.Finally,the configuration of the brake disc is changed for comparative analysis.Firstly,the theory of finite element,modal analysis and thermal analysis and the Hyper Mesh and ANSYS software used in this paper are introduced.On this basis,the three-dimensional model of brake disc and friction plate is built,and the finite element model is obtained by Hyper Mesh mesh mesh,and the fitting curve of heat flow density,convective heat transfer coefficient and brake pressure is obtained by referring to the empirical formula.Secondly,the modal and thermal analysis are carried out in ANSYS.The modal analysis of the brake disc and the friction plate shows that the minimum natural frequency of the two is much higher than the working frequency,and the minimum interval is 104.1hz.The simulation of the temperature rise of the brake disc shows that the maximum temperature of the friction ring is 214.05 ℃ at 2.40 s.It is found that the maximum equivalent stress is 207 MPa at 1.8s.Finally,through the brake disc to make a round hole,change the number of heat sink plate,change the heat sink plate thickness three ways to carry on the simulation comparison analysis.By making 45 round holes with a diameter of 10 mm,the maximum temperature of the brake disc is reduced by 0.47%,which serves the purpose of powder discharge cleaning.The quality is reduced by 3.16%,and the thermal stress is increased by 18.84%.Increase the number of heat dissipation ribs to60,reduce the maximum temperature of brake disc by 0.3%,reduce the thermal stress by 9.96%,increase the quality by 3.37%,increase the related cost;The thickness of the heat sink plate is changed to 14 mm,the thermal stress of the brake disc is reduced by 0.47%,the mass is reduced by 1.16%,and the maximum temperature is increased by 4.16%.By reducing the number of heat dissipating ribs to 15 and increasing the thickness of heat dissipating ribs to 14 mm,the minimum natural frequency interval of brake disc and friction plate is increased by 31.70% and 43.32% respectively,which makes the braking safer.