Finding the best design within limited time: A comparative case study on methods for optimization in structural acoustics

A combination of a commercially available finite element software package and additional user-written programs is used to modify the shape of a square plate made of steel. The structure's local geometry modification values at the selected surface key-points are considered as design variables. The objective of the optimization includes the minimization of the root mean square level of structure borne sound. The optimization process continues automatically until the predefined maximum number of function evaluations is reached. A statistical approach is followed for the comparison of seven different optimization methods. It will be shown that the method of moving asymptotes and the mid-range multi-point method produce the best results to find a substantial improvement of the objective function within a limited number of function evaluations.