Buckling and post-buckling analyses of stiffened composite shells with inter-laminar damages

In the present paper buckling and post-buckling response of axially loaded composite stiffened shell with inter-laminar damage regions have been solved using computer code LS-DYNA. Reduced number of layers and reduced stiffness in damaged region has been investigated. In addition skin delamination with contact model has been used for the analysis of the fracture toughness in the damaged regions. Energy release rates are calculated by Technique-B methodology, employing the 2D shell elements. Mode I and mode II fracture properties are obtained in the damaged regions of the carbon/epoxy composite stiffened shell. The influence of different damages regions on the buckling and post-buckling behavior of stiffened shell is investigated.