High-temperature bending, buckling, and postbuckling of laminated composite plates using the natural mode method

Abstract

In the present study, the behaviour of laminated composite plates under thermally induced loads is examined. A natural thermoelastic theory is developed, based on a linear through-the-thickness temperature variation. The material properties are assumed independent of temperature, but this assumption in no way restricts the generality of the formulation and the developed computer program. The theory is implemented on a model three-node triangular facet finite element which accounts for transverse shear deformation. The underlying principles of the developed methodology lie in the Natural Mode method which is a physically inspired and mathematically consistent method which was conceived with the intention of analyzing large and complex structures. The triangular element neccesitates the computation of a 12 × 12 natural stiffness matrix, and a 12 × 1 thermal (initial) load vector, which makes it probably one of the most inexpensive shell elements available. The effects of large displacements are included in our theory through the geometrical stiffness. In this regard, an Eulerian scheme conceived for the solution of geometrically nonlinear thermoelastic deformation is discussed. The methodology is validated with numerical examples which show the response of multilayered composite plates on thermally or thermomechanically induced bending, buckling, and postbuckling. All composite plates examined have shown remarkable resistance against high-temperature.