THE EQUIVALENT CIRCUIT AND THE SHEAR STRESS OF THE THIN PIEZOCERAMIC COMPOSITE CIRCULAR PLATE

This paper reports the electromechanical equivalent circuit and the shear stress of metal-piezoceramic thin composite circular plate of radius a for simply supported edge. The parameters and the equations of the equivalent circuit are obtained with internal energy of system and energy method to derive equivalent circuit. Provided there is not dissipation in the system, preceding equivalent circuit is always correct at all the frequencies.
The displacement function of damped system at resonance is obtained with the equivalent circuit. Using the displacement function and the dynamic equation, distribution of amplitude of dynamic shear stress is obtained. The amplitude of dynamic shear stress is directly proportional to the product of excited voltage and mechanical quality factor. The shear stress at center of plate is equal to zero. Increases along the radius until to 0.85 a, where the maximum value of shear stress occurs.
The approximate curve of dynamic deformation is in good agreement with the exact curve. However there is considerably more deviation of the approximate distribution of shear stress from exact distribution.