6 Structural health monitoring of steel plates using modified modal strain energy indicator and optimization algorithms

Abstract

Assessing structural damage in plate structures is a critical issue in various engineering fields such as mechanical and civil engineering. In this paper, an efficient approach based on a modified modal strain energy (MSE) indicator, combined with robust optimization algorithms, is proposed to accurately detect, locate, and quantify structural damage in a square plate structure. A finite element model is built in MATLAB software, and the damage is simulated by element stiffness reduction. This approach precisely identifies single and multiple damages by incorporating frequency response in the MSE method. An optimization problem is then formulated using an objective function based on the modified indicator to determine the extent of the damage. The approach is evaluated using three optimization algorithms: Snake optimization, marine predators algorithm, and moth flame optimizer (MFO). Results show that the approach accurately locates and quantifies damage in all examined cases. The MFO algorithm yields superior outcomes in terms of convergence, CPU time, and accuracy of damage extent.