Delamination damage might occur in laminated composites due to defects in manufacturing process or due to low velocity impact during the operating phase of the structure. A three-dimensional geometrically non-linear finite element code is developed for estimation of strain energy release rate components along the delamination front in laminated composite panels under compressive loads along the panel edges. Super-elements containing upto 8-layers with different fiber orientation is developed to decrease the computational effort. Geometrically non-linear analysis is carried out using Lagrangian formulation. The special feature of the code is the development of numerical integration procedure to evaluate strain energy release rate components in three modes of fracture along delamination front. Development of Modified Virtual Crack Closure Integral (MVCCI) equations becomes complicated for three-dimensional fracture analysis. Numerical integration scheme works efficiently and this code was used to analyze standard problems to validate the procedure. Typical numerical results are presented on carbon composite laminated structures. Depth-wise variation of delamination in composite panel was assessed for damage tolerance levels for uni-axial compressive loading case.
展开▼
