Stiffener debonding mechanisms in post-buckled CFRP aerospace panels

Charlotte Meeks, Emile Greenhalgh, Brian G Falzon

Research output: Contribution to journalArticlepeer-review

66 Citations (Scopus)


This paper describes the fractographic analysis of five CFRP post-buckled skin/stringer panels that were tested to failure in compression. The detailed damage mechanisms for skin/stiffener detachment in an undamaged panel were characterised and related to the stress conditions during post-buckling; in particular the sites of peak twist (at buckling nodes) and peak bending moments (at buckling anti-nodes). The initial event was intralaminar splitting of the +45 degrees plies adjacent to the skin/stiffener interface, induced by high twist at a nodeline. This was followed by mode II delamination, parallel to +/- 45 degrees plies and then lengthwise (0 degrees) shear along the stiffener centreline. The presence of defects or damage was found to influence this failure process, leading to a reduction in strength. This research provides an insight into the processes that control post-buckled performance of stiffened panels and suggests that 2D models and element tests do not capture the true physics of skin/stiffener detachment: a full 3D approach is required.

Original languageEnglish
Pages (from-to)934-946
Number of pages13
JournalComposites Part A: Applied Science and Manufacturing
Issue number7
Early online date26 Jan 2005
Publication statusPublished - Jul 2005

ASJC Scopus subject areas

  • Ceramics and Composites

Cite this