Structural parameters identification using improved normal frequency response function method

An improved method that is based on a normal frequency response function (FRF) is proposed in this study in order to identify structural parameters such as mass, stiffness and damping matrices directly from the FRFs of a linear mechanical system. This paper demonstrates that the characteristic matrices may be extracted more accurately by using a weighted equation and by eliminating the matrix inverse operation. The method is verified for a four degrees-of-freedom lumped parameter system and an eight degrees-of-freedom finite element beam. Experimental verification is also performed for a free-free steel beam whose size and physical properties are the same as those of the finite element beam. The results show that the structural parameters, especially the damping matrix, can be estimated more accurately by the proposed method.