Steel wire electromechanical impedance method using a piezoelectric material for composite structures with complex surfaces

Electromechanical impedance (EMI) method is a relatively new non-destructive evaluation technique in the field of structural health monitoring. The method has shown promising results to be recognized as a useful tool for improving the reliability of structures. In general, a lead–zirconate–titanate (PZT) ceramic material is used for EMI method, with the advantage of a single PZT element being able to act as an actuator and a sensor simultaneously. With the increase in use of composites as a building material, the safety issues are gaining more attention. One of the major problems for the EMI method is the brittleness of the PZT material, thus making it difficult for it to be attached on structures with complex geometry. In this study, a technique is presented to overcome the aforementioned problem by coupling a steel wire with a PZT element. Progressive damage, debonding and deterioration scenarios were created and evaluated with the application of the proposed steel wire EMI method.