A Finite Element Iterative Approach for Analysis of Laminated Composite Structural Elements

A continuous mixed field iterative scheme based on a three-dimension finite element displacement method is presented. This method is very powerful in determination of stress distribution for problems with either material and/or geometric discontinuities. For laminated composite materials this method is reliable in stress evaluation at locations away from the optimal Gauss points such as free edges near a notch or a hole. It is also useful in determination of inter-laminar stresses at an interface of laminated composites. Numerical results of two problems are presented. The first problems is to evaluate inter-laminar stresses of laminated composite beams and plates under in-plane loads. The second problem is to obtain stress distribution (also stress concentration factor) of finite unidirectional composite plates with a circular hole at the centre of the plate. The proposed method needs lower computer storage and less CPU time than most of the other schemes. Easy of implementation is another advantage of this method. Since there are no changes to the finite element solutions, the iterative part can be implemented as a post-processing subroutine in any existing program for anisotropic materials without altering the plain body of the code.