Truss Structure Integrity Identification Using PZT Sensor-Actuator

TLDR

The technique uses piezoceramic (PZT) elements as integrated sensor‑actuators to acquire the truss’s impedance signature, differing from conventional modal analysis. The paper introduces a frequency‑domain impedance‑signature method for health monitoring of assembled truss structures and presents the first concept of localizing sensing/actuation areas for damage detection. A PZT patch bonded to a truss node measures its electric admittance, which is coupled with the mechanical impedance to monitor the truss’s signature pattern; the admittance of the damaged truss is compared to that of the healthy truss, and a statistical algorithm extracts a damage index from the signature difference. Experimental results show that a bonded PZT sensor’s detection range is limited to its immediate neighborhood, enabling accurate damage location in complex real‑world structures with minimal modeling and computation.

Abstract

This paper presents a frequency domain impedance-signature-based technique for health monitoring of an assembled truss structure. Unlike conventional modal analysis approaches, the technique uses piezoceramic (PZT) elements as integrated sensor-actuators for acquisition of signature pattern of the truss. The concept of the localization of sensing/actuation area for damage detection of an assembled structure is presented for the first time. Through a PZT patch bonded to a truss node and the measurement of its electric admittance, which is coupled with the mechanical impedance of the truss, the signature pattern of a truss is monitored. The admittance of a truss in question is compared with that of the original healthy truss. Statistic algorithm is then applied to extract a damage index of the truss based on the signature pattern difference. Experimental proof that over a selected band, the detection range of a bonded PZT sensor on a truss is highly constrained to its immediate neighborhood is presented. This characteristic allows accurate determination of the damage location in a complex real-world structure with a minimum mathematical modeling and numerical computation.