An improvement of modal strain energy method for damage detection in plates

Abstract

This paper presents an improved modal strain energy (MSE) method for damage detection in plate-like structures. Firstly, the theory of MSE method established for plate-like structures is briefly outlined, in which a two-step MSE-based procedure (global step and local step) is proposed to enhance the accuracy of detecting the damage’s location and severity. A rectangular aluminum plate constrained by fixed boundary conditions is investigated in order to verify the feasibility of the proposed method. The plate’s finite element models are analysed to obtain natural frequencies and forms of vibration before and after the occurrence of crack. A damage index is presented to identify the location of crack in the plate-like structures. The analytical results show that the global MSE step identifies the damage zone in the plates; the local MSE step accurately detects the crack length and form in the damage zone.