Active self-sensing module for sensor diagnosis and structural health monitoring

For the development of a reliable structural health monitoring system (SHM), it is critical to inspect the performance of the sensors deployed for SHM. In this study, a sensor self-diagnosis scheme is developed specifically for actives sensing devices commonly used for generating and measuring guided waves. First, a self-sensing circuit is designed to allow simultaneous sensing and actuation of guide waves using a single active sensing device. Then, the self-sensing feature is leveraged to develop sensor self-diagnosis schemes for detecting cracking and debonding of the active sensing device. The feasibility of sensor self-sensing and self-diagnosis is investigated through numerical simulations and experiments of a simple cantilever beam. The numerical and experimental results exemplify the potential usefulness of the proposed sensor self-diagnosis scheme for detecting sensor defects and distinguishing sensor malfunction from structural damage.