Structural-Acoustic Design Sensitivity Analysis based onDirect Differentiation Method with Different ElementTypes

Engineers have started to develop ways to decrease noise radiation. Structural-acoustic design sensitivity analysis can provide information on how changes in design variable affect the radiated acoustic performance. As such, it is an important step in the structural-acoustic design and in optimization processes. For thin structures immersed in water, a full interaction between the structural domain and the fluid domain needs to be taken into account. In this work, the finite element method is used to model the structure parts and the boundary element method is applied to the exterior acoustic problem. The formula of the sound pressure sensitivity based on the direct differentiation method is presented. The design variable can be chosen as the material parameters, structure and fluid parameters, such as the fluid density, structural density, Poisson's ratio, Young's modulus, structural shape size and so on. Numerical examples are presented to demonstrate the validity of the proposed algorithm. Different types elements are used for the numerical solution, and the performance of different types of FE/BE element is presented and compared.