Finite element model updating of damped structures using vibration test data under base excitation

Abstract

A new method to update the finite element models of damped structures using vibration test data under base excitation is presented in this paper, which is used on the model updating of a simplified satellite structure. The main idea of the presented method is to update stiffness, mass and damping parameters of the finite element model using vibration test data under base excitation. Updating of damping parameters plays an important role in the calculation of system response. A simulated numerical case is used to prove the effectiveness of the proposed method, and the proper order of parameters to be updated is studied in the mean while. From the result of the comparative study, physical parameters like stiffness and mass should be updated prior to damping parameters. By the idea of “step by step” updating, the proposed method is used to update a simplified satellite model. In the process of updating, the sensitivity of parameters is studied before the updating, which leads to a better selection of updating parameter. After the updating, responses of key nodes predicted by the updated model matches the test result well in all measured direction.