A response reconstruction method based on empirical mode decomposition and modal synthesis method

Abstract

With the increasing the complexity of civil structures and diversity of the structural components, reconstructing the responses of complex civil engineering structures based on the conventional time-domain reconstruction method is very challenging. Apart from the massive computer storage needed in the calculation process, the enormous calculation times may also hinder the response reconstruction of the civil structures. This paper proposes a novel strategy of the time-domain reconstruction method by combining the modal synthesis method and empirical mode decomposition with intermittency criteria in the time domain. The response reconstruction method is conducted at two levels. The first level is performed on the reduced super-element from the interface DOFs to the internal DOFs of the critical substructure, and then at the element level to extrapolate dynamic responses at critical locations. In each level’s reconstruction, the number of calculation parameters decreases significantly. The response of the whole structure can be quickly obtained at one time, not only decreasing the computation time but also ensuring reconstruction accuracy. The numerical studies and experimental validation are both conducted on a simply supported beam and a complex cooling tower for verification, and the effects from some external parameters, including measurement noise, the order of substructural normal modes, the number of substructures and the number of sensors, are considered. The results illustrate that the proposed reconstruction method based on the modal synthesis method improves the calculation effectiveness considerably and ensures accuracy.