Optimization of vibration suppression effect of disc brake based on quadratic response surface algorithm

To achieve the dual improvement of weight reduction and vibration damping of brake discs on the premise that heat transfer performance and strength performance were not attenuated, a multi-objective optimization scheme based on the response surface algorithm was proposed. Firstly, considering the influence of thermal stress on the natural frequency of brake discs, a thermal-structural-modal coupling analysis model of the braking system was established. The transient temperature field, transient stress field and pre-stress modal response characteristics were obtained, and the accuracy of the finite element model was verified through temperature and modal tests. Secondly, experimental design was carried out based on Central Composite Design (CCD), and the quadratic response surface method was introduced to construct a surrogate model, so as to realize the mathematical expression of natural frequency, peak temperature, peak stress and mass. Finally, a multi-dimensional optimization mathematical model was constructed. With the minimum mass as the objective, combined with the Sequential Quadratic Programming (SQP) algorithm, the first-order natural frequency was optimized to the range of 1400-1800 Hz on the premise that the peak thermal stress was not increased. The research results showed that under the condition of meeting the multi-objective optimization requirements, the mass of the brake disc could be reduced by more than 3.5 %. The proposed thermal-structural-modal coupling analysis model solved the problem that the traditional modal calculation had a large deviation from the actual boundary conditions. The applied quadratic response surface surrogate model realized multi-objective collaborative optimization, which had important engineering value for improving the NVH performance of automobiles, alleviating the continuous excitation of the brake disc friction pair and the modal coupling resonance between components, and promoting the development of automotive lightweighting and intelligentization.