Multi-objective optimization of the layout of damping material for reducing the structure-borne noise of thin-walled structures

A multi-objective optimization of the layout of damping material for reducing the structure-borne noise of an enclosed cylindrical thin-walled structure was investigated by using the panel acoustic contribution (PAC) method and response surface methodology (RSM). Critical frequencies of each excitation were obtained by the control equations of structural-acoustic coupling system. The acoustic contributions of panels with different excitations at critical frequencies were calculated by the PAC method. Combined with the correlation coefficient matrix (CCM) method, the sum of panel acoustic contribution (SPAC) was proposed to identify and group the panels with different acoustic contributions under multiple excitations. In order to reduce the noise, a damping material was pasted. The thicknesses of the damping material applied to different groups were used as the design variables of the response surface functions, the sample data obtained by the finite element model was used to achieve the response surface functions for each excitation. Through these response surface functions, a multi-objective optimization model for discrete thicknesses of the damping material was established to reduce the structure-borne noise, and the optimization calculation was carried out by using genetic algorithm (GA). It is shown that the structure-borne noise was reduced more without increasing the amount of the damping material, and the present method is efficient enough to study and reduce the structure-borne noise. Compared with the traditional finite element nonlinear coupling calculation, the present method is more feasible and efficient.