Mechanism Analysis And Optimization Of Brake Judder Of Automotive Disc Brake

As a typical vehicle fault,brake judder brings harm to the ride comfort and safety of the vehicle.It has been more than 30 years since the problem of brake judder was first put forward.Researchers at home and abroad have made some achievements in the research of this problem.However,after summarizing these research results,the author found that there are some irrationalities in the research process of judder,which can be summarized into two aspects: firstly,there are some over idealized assumptions in the construction process of the dynamic model used to predict the brake judder,which leads to large errors in the prediction results.On the other hand,the research on the optimization of brake judder from the perspective of system is relatively insufficient.Based on the shortcomings in the research of brake judder,this paper will carry out research work from two aspects of mechanism research and optimal design of brake judder,mainly including:Firstly,a dynamic model based on disc-pad surface spring contact is proposed.The input and friction characteristics of the system are dealt with according to the actual working conditions.Then the Simulink model of the dynamic model is simulated and calculated,and the corresponding judder bench test is designed to verify the correctness and validity of the model.The results show that the improved dynamic model proposed in this paper is correct and applicable in predicting the occurrence of brake judder.Secondly,from the aspect of vibration source control,this paper combines the calculation formula of BTV(Brake torque variation)and BPV(Brake pressure variation)to find out the key parameters that affect the brake judder.On this basis,taking the minimum of BTV as the optimization objective function,two kinds of judder optimization schemes are proposed to optimize the structure of caliper and the steel back of brake pads.Then,this paper proposes a simple and efficient method to determine the parameters of the optimized brake system.Based on the determination of parameters,the time-domain response of brake pressure and brake torque and the time-varying curves of BTV and BPV are obtained by substituting them into the improved disc-pad spring contact dynamics model.The simulation results show that the judder characteristics are consistent with the conclusions of judder mechanism research.Finally,using the Simulink model of the dynamic model of the brake disc-pads surface spring contact proposed in this paper,the system before and after the optimization is simulated to obtain the time-domain response of the brake pressure and the brake torque,and the results of the brake BTV and BPV vary with time.Then,the results before and after the optimization are compared and analyzed,and it can be concluded that the research direction of the optimization of the brake judder in this paper can reduce the brake judder in the early stage of vehicle design,the purpose is to provide certain research ideas for vehicle enterprises in the search of brake judder avoidance technology.