An Application of SOL 400 to Support the Design of Damaged CFRP Stiffened Panels

The aim of this work is to show an application of the SOL 400 of MSC Nastran® in order to investigate the final failure response of damaged composite stiffened panels in post buckling regime, by using progressive failure analysis (PFA) methodology. This methodology has been applied in order to support the design of composite stiffened panels by predicting the initiation of the local failure and its propagation up to the final collapse of the panel, in presence of local damage (barely visible impact damage, BVID) and in post-buckling regime. Discrete damages have been considered in the skin of the panel. According to the indications enclosed in many guidelines for the preliminary design of composite structures, a simplified model of BVID has been considered in this work, in particular by simulating this kind of damage with a hole of 1/4 inches in diameter. The collapse load of the panel has been evaluated both for different locations of a single damage and for multi-damage scenarios. The results of the analyses illustrate the combined effect of the reduction of the panel stiffness and of the damage propagation, and also the sensitivity of the residual strength of the panel with respect to different damage locations and damage density.