Electrode Mechanics of Piezoelectric Materials

Many piezoelectric materials and structures are operated under increasing high electric and mechanical loads. The electric fields are applied through internal or external electrodes. The electromechanical interaction of piezoelectric ceramics with electrodes is of great importance. In this paper, the current advance on the electrode mechanics of piezoelectric materials is reviewed and the closed-form solutions of the electrode tip fields for various electrode geometries are introduced. Then, the problem of a piezoelectric layer with a straight elastic electrode on its surface is studied. The electrode is treated as an elastic layer and can sustain mechanical stresses. As a result, the stress singularity near the electrode tip is identified. Relationship between the electrode tip field and the thickness of the piezoelectric layer is established. The stress and electric displacement intensity factors at the electrode tip are obtained to show the effect of layer thickness and the applied electric field. Solution technique for two identical and collinear surface electrodes on the piezoelectric layer is also provided and the effect of relative distance between the electrodes is explored. Further, nonlinear electrode tip behavior is discussed.