HIGH-TEMPERATURE BENDING, BUCKLING, AND POSTBUCKLING OF LAMINATED COMPOSITE PLATES USING THE NATURAL-MODE METHOD

In the present study, the behaviour of laminated composite plates unde r thermally induced loads is examined. A natural thermoelastic theory is developed, based on a linear through-the-thickness temperature vari ation. The material properties are assumed independent of temperature, but this assumption in no way restricts the generality of the formula tion 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 develop ed methodology lie in the Natural Mode method which is a physically in spired and mathematically consistent method which was conceived with t he intention of analyzing large and complex structures. The triangular element neccesitates the computation of a 12 x 12 natural stiffness m atrix, and a 12 x 1 thermal (initial) load vector, which makes it prob ably one of the most inexpensive shell elements available. The effects of large displacements are included in our theory through the geometr ical stiffness. In this regard, an Eulerian scheme conceived for the s olution of geometrically nonlinear thermoelastic deformation is discus sed. The methodology is validated with numerical examples which show t he response of multilayered composite plates on thermally or thermomec hanically induced bending, buckling, and postbuckling. All composite p lates examined have shown remarkable resistance against high-temperatu re.