Sensitivity-based finite element model updating using dynamic condensation approach

Abstract

An accurate finite element (FE) model is frequently used in damage detection, optimization design, reliability analysis, nonlinear analysis, and so forth. The FE model updating of large-scale structures is usually time-consuming or even impossible. This paper proposes a dynamic condensation approach for model updating of large-scale structures. The eigensolutions are calculated from a condensed eigenequation and the eigensensitivities are calculated without selection of additional master DOFs, which is helpful to improve the efficiency of FE model updating. The proposed model updating method is applied to an eight-storey frame and the Jun Shan Yangtze Bridge. By employing the dynamic condensation approach, the number of iterations for the eigensensitivities is gradually increased according to the model updating process, which contributes to accelerate the convergence of model updating.