A non-intrusive dynamic sensitivity-based substructure model updating method for nonlinear systems

Abstract

In nonlinear finite element model updating (FEMU), one of the main challenges is how to improve the updating efficiency for large-scale structures. The computational time of updating depends on the degree-of-freedom of the finite element model, and the optimization algorithm that the user chooses. In this work, a novel dynamic response sensitivity-based nonlinear FEMU method using the substructures is presented to reduce the time consuming of computation and updating. Considering the residual structural modes, the enhanced Hurty/Craig-Bampton (EHCB) substructure method is developed to establish a more precise initial numerical model, which also has high computational efficiency. A non-intrusive algorithm based on the real and imaginary perturbation of updating parameters is implemented to compute the nonlinear substructural response sensitivities, and further reduce the iteration loops in the nonlinear FEMU process. Simulation examples with smooth and non-smooth localized nonlinearities are conducted to verify the accuracy, robustness, and efficiency of the proposed method. Results indicated that the proposed method can effectively and efficiently update the nonlinear finite element model with high accuracy.