A computational model for analysing interactive buckling and delamination growth in composite structures

In this paper, a unified method is presented: (i) to model delaminated stiffened laminated composite shells; (ii) for synthesising accurate multiple post-buckling solution paths under compressive loading; and (iii) for predicting delamination growth. A multi-domain modelling technique is used for modelling the delaminated stiffened shell structures. Error-free geometrically nonlinear element formulations - a 2-noded curved stiffener element (BEAM2) and a 3-noded shell element (SHELL3) - are used for the finite element analysis. An accurate and simple automated solution strategy based on Newton type iterations is used for predicting the general geometrically nonlinear and postbuckling behaviour of structures. A simple method derived from the 3-dimensional J-integral is used for computing the pointwise energy release rate at the delamination front in the plate/shell models. Finally, the influence of post-buckling structural behaviour and the delamination growth on each other has been demonstrated.