On the behaviour of impact damaged CFRP laminates

Abstract

The load-carrying capacity of composite structures in aircraft, spacecraft, etc. is expected to be greatly influenced by inherent defects or damages induced during utilisation. This paper reports on the ongoing experimental research in DFVLR WB-BK pertaining to the effect of simulated defects on the fatigue behaviour and residual strength of CFRP laminates. Two special kinds of mechanically produced damage in thin laminates caused by dropped tools are the main topics of this paper: a three-square indentation generated by a tapered triangular tip and a delamination zone produced by a ball-shaped tip. The investigated material is epoxy resin reinforced with T300 carbon fibre with various orientation sequences.