SH Waves in Orthotropic Functionally Graded Plates with Initial Stress

Because of the limitation of manufacturing technology, the initial stress in functionally graded material (FGM) structures is inevitable. Based on the theory of "Mechanics of Incremental Deformations", the SH wave propagation in FGM plates under initial stress are investigated. The Legendre polynomial series method is used to solve the wave equation with variable coefficients. Numerical results show that the effects of the initial stress in the thickness direction are very different from those in the wave propagating direction, both on the dispersion curves and on the stress shapes.