Dynamic Focusing Effect of Laminated Piezoelectric Structures Subjected to Radial Impact

Abstract

This article presents an analytical solution to reveal some of the phenomena of the dynamic focusing effect of the laminated structures composed of the piezoelectric fiber and the matrix layer subjected to the radial impact load. The dynamic focusing effect gives rise to very high stress magnitudes and electric potential at the center or near the center of piezoelectric fibers, which easily results in a breakage along the axial direction of the piezoelectric fiber at the higher tensile stress region. The electroelastodynamic equation for the laminated cylindrical piezoelectric structures is solved by means of the integral transforms. The unknown constants involved are determined by using the interface continuity conditions between the piezoelectric fiber and the matrix layer, and the boundary condition at the external surface of the laminated cylindrical piezoelectric structure. From the analytical expressions and the numerical examples for the two kinds of piezoelectric fibers, PZT-4 and BaTiO3, it is found that the dynamic focusing effect is dependent on the material property of the piezoelectric fibers, so that the maximum dynamic focusing effects of the two kinds of piezoelectric fibers occur at different radial points. It is significant to know the mechanism of the dynamic focusing effect of the laminated cylindrical piezoelectric structures subjected to the radial impact load to evaluate the dynamic strength and the electric excitation signal of the composite structures with the piezoelectric fiber and the matrix layer.