Incremental Deformations in Orthotropic Laminated Plates Under Initial Stress

Abstract

Plate equations for the incremental deformation in composite plates with orthotropic constituent layers are derived according to Trefftz’s formulation for elastic bodies under initial stress. The plate theory thus derived includes the microdeformation which can account for the heterogeneity of the plate. Flexural wave propagation under initial stress and buckling of a simply supported rectangular composite plate are investigated. In a special case of harmonic wave propagation in a free composite plate dispersion curves predicted by the plate equations are compared with the exact curve. Good agreement is observed for the complete plate theory and Approximation I, while the adequacy of the other two sets of simplified equations, Approximations II and III, depends vitally on the ratio of the transverse shear rigidities of the constituent materials.