Identification of joint structural parameters between substructures

A new methodology of combining the finite element model of a complex structure with its model obtained by experimental modal analysis techniques is presented to identify the joint stiffness and the damping characteristics between its substructures. First, the modal parameters of the structure with joints are extracted based on experimental data using Autoregressive Moving Average Vector models. Then, a condensation technique based on the Riccati iteration algorithm and the orthogonality conditions is applied to reduce the matrix order of the finite element model to match the order of the experimental model. Comparing the two models, the unknown joint parameters are estimated based on the least squares method. The accuracy and the effectiveness of the proposed method were verified through simulation studies.