Crack Detection in Structural Systems Using Electro-Mechanical Signatures

A modified model combining EMI technique and RMM is proposed to quantitatively correlate crack parameters with piezoelectric signatures for structural health monitoring. The structural members are modeled as Timoshenko beams for flexural motion and as the classical longitudinal rods for axial motion as well as the cracks are treated as massless rotational springs. For a structural member with surface-bonded PZT wafer, a coupled system is considered. Then, an analytical expression of impedance involving information of cracks is derived. Based on this model, EMI signatures extracted from the PZT wafers can be used to identify cracks in a structural system.