Damage Detection in Plates with Different Boundary Conditions Using Improved Modal Strain Energy Method

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 with different boundary conditions is briefly outlined. Therein, two-step MSE-based procedure, which is global step and local step, is proposed to enhance the accuracy for detecting the location and severity of damages. An aluminum rectangular plate is investigated in order to verify the feasibility of the proposed method. The plate’s finite element models are analyzed to obtain natural frequencies and mode shapes for before and after the occurrence of damage. A damage index is presented to assess the accuracy of the proposed method. The analytical results show that the global MSE step well identifies the damage zone in the plate; then, the local MSE step accurately detects the crack’s length in the damage zone.