Abstract: Inview of the difficult parameterization problem of complex structural shape, a parameterized shape optimization model based on finite element meshes is built and a structural shape optimization method based on mode shape is proposed for controlling the structural acoustic radiation power. In this method, structural vibration characteristic analyed by using finite element method and then structural acoustic radiation is analyzed by using Rayleigh integral. On the basis, the shape optimization function of modification domain is defined by using a linear combination of a group of mode shape absolute values, and each mode shape contribution factor is taken as a design variable. The structural shape is optimized by changing the mode shape contribution factors to decrease the structural acoustic radiation power. Structural acoustic radiation optimization is studied under harmonic excitation, the average value of acoustic radiation power in the analysis frequency band acoustic radiation is taken as design objective, the maximum variable value of structural coordinates and mode frequency are taken as design constraints, and the problem is solved by using sequential quadratic programming. Numerical examples of a plate and complex surface are presented to show that structural acoustic radiation can be controlled effectively.

Key words: Mode shape, Shape optimization, Structural acoustic radiation, nozzle size selection numerical simulation partial flow drift rate