Analysis Of Bonding Properties Between Piezoelectric Wafer And Host Structures And Its Application

In civil engineering, structures will appear varying degree of damage due to the long-term effects of various factors. The main issue of structural health monitoring is how to identify the damage qualitatively and quantitatively. Piezoelectric materials have been widely used in structural health monitoring because of their electromechanical coupling effect.Since most piezoelectric materials is used in the form of piezoelectric patch surface bonded to the host structures, the effect of the adhesive layer is very important. Unfortunately due to the shear lag effect of adhesive layer, the deformation of the structure cannot be completely transferred to the piezoelectric patch. In this paper, quantitative analysis of shear lag effect has been done based on the electromechanical coupling theory. The influences of various parameters are also discussed in detail including the dynamic effects and electric resistant of the circuit. Then some advices are given to reduce the shear lag effect.In structural health monitoring, electro-mechanical impedance (EMI) technology is developing. This method uses the impedance (admittance) spectrum of piezoelectric patch-adhesive layer-host structure to identify the structural damage. This paper discussed the impedance spectrum of piezoelectric patch-adhesive layer-host structure under different damage parameters through model experiment and numerical simulation.Considering the geometric characteristics of piezoelectric patches, a new beam element surface bonded with piezoelectric patch is developed and implemented using MATLAB. The comparison with the commercial finite element software is made to verify the proposed elements. The numerical results also show that the proposed element has a great advantage in computational efficiency.