Abstract
This paper presents a quantitative structural health monitoring technique to evaluate tensile force in a thin beam and stress field in a thin plate. This technique is based on the smart structure concept, which a piezoceramic material (PZT) bonded on the surface of a structure works simultaneously as an actuator and a sensor. To evaluate the stress state inside a structure, electrical impedance before and after applying tensile force are measured. Based on the wave propagation theory, a structural model of the beam containing the PZT is formulated and the measured electrical impedance is derived analytically. A tensile force identification method in the beam is proposed by using an optimization technique. For a plate case, FEM model is used in formulation. With experimental verification, it is found that the analytical results and the tensile force in beam case can be identified with accuracy. By using the proposed method, it is possible to identify value of the tensile force in a thin beam from only one measurement.
