Characterization of nonlinear dynamic response of a thermally loaded and harmonic excited composite plate with initial geometric imperfection

This paper focuses on characterization of the nonlinear dynamic response of a thin composite plate with initial geometric imperfection subjected to combined thermal and harmonic loadings. A theoretical formulation based on Kirchhoff thin plate theory and von-Kármán type kinematic relation is presented in terms of deflection and Airy stress function. A reduced-order model, which incorporates initial global geometric imperfection and equivalent in-plane boundary constraints, is developed. The governing partial differential equation is discretized to a coupled nonlinear system through Galerkin technique, which includes quadratic and cubic terms associated with initial geometric imperfection and mid-plane stretching. The number of spatial modes used in the expansion of the deflection has been investigated by comparison of the post-buckled deflection and dynamic in-plane strain response with the results obtained through the direct integration finite element method. The effects of the temperature rising, plate geometry, equivalent in-plane boundary compliance and initial geometric imperfection on the dynamic behaviour are investigated through a detail parametric study.