Experiment investigation on impact damage and influences on compression behaviors of single T-stiffened composite panels

In this paper, aiming at better understanding the damage tolerance of T-stiffened composite panels, impact damage and the influences on compression behaviors were studied with experiment methods using single T-stiffened panels. Low velocity impact (LVI) was conducted on the stiffener flange tip from the smooth side. Serious impact damage, including stiffener/skin interface debonding, fibre breakage and delamination, was observed. After the impact test, compression experiment was performed to characterize both the buckling behavior and compression failure mechanism. The compression results revealed that the buckling was promoted by the impact damage and induced bending moments which drove delamination inside the skin to propagate beneath the stiffener and led to the failure of the stiffened panel. Consequently, the impact damage decreased the buckling load and failure load of the single T-stiffened panel by 9.62% and 34.1%, respectively.