Structural Health Monitoring by Piezo-Impedance Method

Abstract

This paper presents a fundamental study of a structural health monitoring technique called the piezo-impedance method, which utilizes an electromechanical property of piezoceramics. For a thin beam with tensile force, an analytical model of the piezo-impedance method is formulated based on the wave propagation theory. Also, a tensile force identification method in a thin beam combined with optimization techniques is proposed. An experiment is performed with small test pieces of a beam to investigate the validity of the proposed method and it is found that analytical results are in good agreement with experimental measurement results and that the tensile force is identified with accuracy. By using the proposed method, it is possible to identify absolute value of the tensile force in a beam from only one measurement.

Quantitative health monitoring of bolted joints using a piezoceramic actuator–sensor

“…This is because the wavenumber is modified by the application of tension or compression. The member will be stiffened by tension and be softened by compression [6,9]. This is the effect of tensile force on the strength of the member.…”

“…(8) The density and thickness are uniform over the beam. (9) The static force F is applied uniformly along the crosssectional area.…”

“…This approach encourages the development of numerical models to cooperate with the use of PZT actuator-sensors in order to develop a quantitative health monitoring technique. Recently, Miyashita et al [9] used a PZT actuator-sensor to measure the tensile force in thin beams by utilizing the SEM modelling. However, no precise model of bonded PZT patches was used in their study.…”