Nonlinear transient response of functionally graded plates with general imperfections in thermal environments

This paper deals with the nonlinear transient response of simply supported imperfect functionally graded plates in thermal environments. An imperfection function is used to model general forms of initial geometric imperfections including sine type, global type and localized type imperfections. It is assumed that the plate is subjected to a temperature field uniform over the plate surface but varying along the thickness direction due to steady-state heat conduction. The theoretical formulations are based on the higher-order shear deformation plate theory and von Karman-type nonlinear kinematics. The asymptotic solution is obtained by using an improved perturbation approach, Galerkin technique, and Runge-Kutta iteration process. The material properties of the plate are temperature-dependent and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. Numerical illustrations are given in both tabular and graphical forms. It is shown that imperfection mode and magnitude have significant effects on the nonlinear transient response of functionally graded plates. The influences of imperfection location, temperature field, and volume fraction index are also studied. (C) 2007 Elsevier B.V. All rights reserved.