Abstract:A modified electro mechanical impedance model of one dimensional beam is presented in this study.The presented model references the structure mechanical impedance analytical expression of one dimensional beam getting from the free beam vibration theory.The effect of the adhesive layers on the dynamic interaction between piezoelectric actuators sensors (PZT) and host beam is also taken into account.The modified model is used for performing the numerical simulation of the PZT coupling electric impedance spectrum in the 5~80 kHz range,when the bonding coefficient ξ is 0.01,0.02 and 1.0,respectively.The adhesive strength of three kinds of adhesives,α cyanoacrylate,epoxy resin and modified acrylate, are obtained by measurement and calculation, which is 0.882 MPa,7.621 MPa and 10.198 MPa,respectively.Then the PZT coupling electric impedance spectrum of the beams using the three different adhesives is measured in the range of 5~80 kHz as the numerical simulation.The result shows that the coupling impedance spectrum of numerical simulation corresponds with the experimental result very well, and the relative error of the peak corresponding frequency between them is 0.25%~6.06%.