Simulation Optimization Of Disc Brake Based On Complex Modal Analysis

With the increasing popularity of automobiles,consumers demand more and more excellent of the indicator of the automobiles' performance,expecting a more comfortable and stable experience and a more tranquil environment within the car.In this context,great importance is increasingly being attached to the NVH performance of automobiles.The NVH brake is the key of vibration and noise research.It is of great significance to employ reasonable control measures to suppress the braking noise.Based on the actual engineering issues of a domestic brake manufacturer,aiming at the noise problem of a certain type of disc brake,this thesis presents a set of measures to suppress the noise of brake based on the research of the main influencing factors and numerical modeling as well as optimization design ideas and the optimal design for the sliding caliper disc brake(chapter 1 and chapter 2).The optimization process is as follows:The finite element analysis model was established based on the actual model of the sliding caliper disc brake combined with the dynamometer test data.The eigenvalues and noise mode shapes was extracted based the ABAQUS software,and the key components that causes the braking noise were thus obtained.Then the amplitudes of the noise modes were compared to conclude that Maximizing the overall amplitude of the brake pads inside was the key of brake noise optimization(Chapter 3).Based on the orthogonal test,analysing the thickness of the radiating ribs,the number of the radiating ribs,the angle of the radiating ribs,the coefficient of friction,the modulus of elasticity and chamfer cut depth six groups of parameters to decrease the tendency of instability of disc brakes.The response rates of the optimal parameters to the target variables were evaluated via max-min difference and variance analysis(Chapter 4).Combining the instability tendency of disc brakes,the service life of brake lining and the braking energy efficiency,a multi-objective evaluation system was established.The three parameters of the friction coefficient,the elastic modulus and the chamfering depth of cut were used as optimization parameters to establish the multi-objective optimization response surface,and the optimal designed parameters were obtained by genetic algorithm optimization(Chapter 5).The optimization scheme was evaluated by complex modal analysis:the tendency of instability of the optimized scheme was 84.62%lower than that of the original scheme,and the maximum amplitude of the main mode decreased overall.The optimization of the scheme was evaluated by the bench experiment:the probability of brake noise in the optimized scheme bench experiment was much lower than that of the original scheme,and the comprehensive score of the bench noise could reach the requirements of the whole plant.Combined with finite element analysis and bench experiment,it proved that the optimization scheme is feasible.(Chapter 6).