The post-buckling response of stiffened CFRP panels using a single-stringer compression specimen (SSCS): a numerical investigation

Abstract

The safe exploitation of the post-buckling region of CFRP panels in aerospace applications is of prime interest here. Due to the long computational time of finite element analysis for the post-buckling response of CFRP panels, there is a need to devise some efficient procedures. Skin/stringer debonding is primarily responsible for the collapse of the stiffened panels under compressive loading. In this study a simplified approach based on a single-stringer compression specimen (SSCS) has been employed to gain an insight into the post-buckling behaviour of CFRP panels under axial compression. A progressive damage model is used to get more accurate numerical results of the post-buckling response of SSCS. The outcomes of the study are compared with the published results and a fair agreement is found. In addition, a comparative study of open-and closed-section stringer stiffened panels based on a global-local approach for predicting pre-buckling, post-buckling and mode shapes is carried out. As the simplified model is used in this study so detailed damage models can be constructed to account for all damage modes: matrix cracking, fibre kinking, fibre fracture, and delamination. The study can be employed as a global-local approach to get the post-buckling response of CFRP stiffened panels. Furthermore, it also provides an efficient mean for the design optimization of CFRP structures in the post-buckling regime.