DYNAMIC RESPONSE RECONSTRUCTION METHOD BASED ON EMPIRICAL MODE DECOMPOSITION AND MODEL CONDENSATION

In terms of performing the dynamic response reconstruction of large civil engineering structures, the efficiency and accuracy of the current time-domain method based on finite elements are low and poor. A dynamic response reconstruction method combining empirical modal decomposition and modal condensation is proposed. Based on the modal synthesis method, the whole finite element model is divided into several sub-structures, and a super-element model with less DOFs is obtained by coordinate transformations. The reconstruction is carried out by combining the empirical modal decomposition method with intermittent criterion. Without considering the boundary conditions of each substructure, this method effectively reduces the dimension of the mathematical matrix of the relevant physical parameters of the finite element model, greatly improves the computational efficiency of response reconstruction, and is suitable for the dynamic response reconstruction of civil engineering structures. The effectiveness of the reconstruction method is verified by a numerical example of a cantilever beam, and the influence of noise and the number of main modes on the reconstruction effect are studied. The results show that the noise level has some influence on the precision of reconstruction, and that the number of main modes has trivial influence on the precision of reconstruction.