A Real-Time SHM System Based on Topological Derivative Methods

In this work we present a Structural Health Monitoring (SHM) system for the inspection of metallic plates using Lamb waves. This system is based on a PWAS (Piezoelectric Wafer Active Sensor) network used for mode selective excitation with in-house equipment for both signal generation and signal measurement. The measured data is processed using the topological derivative, a scalar function that measures the sensitivity of a certain functional to domain perturbations. It will serve as an indicator function to detect the presence of defects. We propose an efficient implementation of the topological derivative algorithm which benefits from the fact that the same equipment is used for excitation and data acquisition, allowing for real-time data processing. We will show a couple of numerical examples of the algorithm’s functioning as an initial proof-of-concept validation of the system.