Effect of initial stress on the propagation behavior of SH-waves in multilayered piezoelectric composite structures

The propagation behavior of horizontally polarized shear waves (SH-waves) in a periodic multilayered piezoelectric composite structure with initial stress is taken into account. The multilayered piezoelectric composite structure consists of piezoelectric layer bonded perfectly with polymer layer alternately. Solutions of the mechanical displacement and electrical potential function are obtained by solving the coupled electromechanical field equations for the piezoelectric layer and the polymeric layer, respectively. The phase velocity equation of the SH-waves in the periodic multilayered piezoelectric structure is obtained for the case of SH-waves propagation along the direction normal to the layering. Influence of initial stress on the stop band effect and the dispersion relation of the SH-waves are discussed in detail, respectively. One set of piezoelectric layer-polymeric layer combination system is considered, i.e. PZP-5H ceramic layer-polythene layer. It can be seen from our research results that the stop band effect of the SH-waves propagation is dramatically changed with the increase of the magnitude of the absolute value of initial stress. The dispersion relation changes remarkably also, as the magnitude of absolute value of the initial stress is greater than 100MPa. The results reported in our research work can be used as the benchmark for the investigation of the wave propagation in the piezoelectric coupled structures and are theoretically significant in the design of wave propagation in the piezoelectric coupled structures as well.