Numerical Structural Optimization With Respect to the Reduction of Structure Borne Sound Using Various Spline Formulations

In this paper a method for optimizing structures numerically with regard to structure borne sound is presented. The finite element method (FEM) is used to calculate the surface velocities of the vibrating structure which is discretized with 3D solid elements. Next, Powell's COBYLA algorithm is used to modify the geometry of the structure in such a way that the level of structure borne sound is reduced. A new FEM input file is generated, and the whole process is repeated iteratively until a stop criterion is met. In order to reduce the number of design variables (and therefore the computation time) the surface of the structure is modeled using spline functions. For a simple example structure the level of structure borne sound is reduced by more than 6 dB.