Structure Optimization Using Coupling Position of Substructure Based on Measured Frequency Response Functions

Abstract

Substructure’s position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics based on a measured frequency response function (FRF). In conventional SDM (structural dynamics modification) method, the layout of modifying substructure’s position is first fixed and from that condition the structural optimization is performed on basis of substructure’s size and/or material property as design parameters. But in this paper as a design variable substructure’s global translational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate structure. KEYWORDS: Structural dynamics modification, eigenvalue, optimization, frequency response function, non-matching node.