A modified hyperbola based baseline free approach using Lamb wave mode conversion for detection of multiple structural damages: a simulation based study

Abstract

Guided wave based techniques are among the promising techniques for structural health monitoring due to their ability to detect damage with high precision, ability to scan large area and low power consumption. However, practical implementation of these techniques to structures with relatively complex geometries such as stiffened plates demand further research due to several challenges. Some of such challenges include the presence of stiffeners and edges in close vicinity causing multiple reflections of waves, possibility of multiple damages and lack of baseline data. To address all these issues, a modified hyperbola based algorithm using mode converted signal and a data based matching scheme has been proposed in this paper. A stiffened plate is taken as the example structure. Corrosion like defects have been considered as the damages. Each panel of the stiffened plate has been scanned separately through phased array actuation. The effectiveness of this technique has been demonstrated using high fidelity 3D finite element simulation data. It’s robustness has been shown through the same finite element model with artificially added small error in actuator placement.