Analysis of shell structural acoustic radiation using finite element method-virtual boundary element method

Virtual boundary element-least square method and finite element method are applied to study acoustic radiation of an enveloped couple shell structure. The formula of virtual boundary element-least square method is founded and the computer program is coded to calculate the acoustic radiation of shell structure. Compared with the common boundary element method, numerical treatment for singular integration is avoided, and the coefficient matrix is a symmetrical one. The method of this paper can also overcome the non-uniqueness problem effectively. In addition, the method is simple in ideas and working out the program is easy. Numerical examples of calculating the surface pressure of pulsate sphere are given. Compared with analytical solution, it is shown that the correctness and accuracy of virtual boundary element-least square method were proved. It analyzed the acoustic radiation with thickness of shell structure, boundary condition, and the location of the force. The studies show that, structural acoustic radiation is notably affected by the changes of all the parameters. The acoustic radiation of the changes of frequency, damping, damping treatment position, and stiffened structure can be calculated by this method. The result is valuable for optimized design of structure with low noise.