A Two-Step Damage Identification Based on Cross-Model Modal Strain Energy and Simultaneous Optimization

Abstract

Aiming at the problem of the effect on damage identification caused by noise and modal incompleteness, a two-stage damage identification method based on cross-model modal strain energy and simultaneous optimization was proposed. This paper proposed an improved damage index (Modified Index of Cross-model Modal Strain Energy, MICMSE) based on cross-model modal strain energy. This method first locates the damaged elements by MICMSE, and introduces simultaneous optimization to quantify the damage ratios of damaged elements. The two-step method avoids the calculation of the sensitivity of the modal parameters and the reanalysis of the characteristic equation, speeds up the convergence speed, and guarantees the recognition accuracy. The results of the numerical example show that the method proposed in this paper can effectively locate the damage elements and identify the damage ratios under different damage cases and noise levels.