Smart Structure Integrity Monitoring Using Transient Response

Abstract

Structural integrity monitoring is a critical process in ensuring safe operation of structures. Damage that is not detected continuously and corrected immediately can cause additional damage and eventually catastrophic failures. In ensuring safe operation, real time damage detection is necessary and is realisable through the use of smart structures. In this paper, a new non-destructive testing method to detect damage in structural connections using piezoelectric actuating/sensing devices is proposed. A thin beam with one end fixed and the other subjected to a variety of boundary conditions is used to investigate the feasibility of this method. The method involves first flexurally exciting the beam and measuring its resulting transient response using a piezoelectric device, and then determining any change in its one variable boundary condition by comparing the measured response to that of a fixed-fixed (or secure) condition. The size of the difference in responses indicates the degree of extent of the boundary change. The proposed transient response approach uses information that is unobtainable using current steady-state harmonic based methods. Results of experiments show significant differences in the transient responses of secure and damaged beam connections.