Experimental Study on Compression Behavior of Fiber-Reinforced Resin-Based Composite Stiffened Panels in Hygrothermal Environment

Fiber-reinforced resin-based composite stiffened panels are put in the hygrothermal box at 70°C and 85% RH until moisture absorption reaches balance. Then, the compression experiments on the common stiffened panels and the stiffened panels after moisture absorption are conducted to get buckling and failure loads. Test results are compared to analyze the effect of damage on the carrying capacity of the structure. The buckling load does not significantly change, but the failure load of the panels after moisture absorption is reduced by 10.2% as compared to the common panels. The failure modes are mainly composed of debonding and fracture of the stiffener, the skin cleavage and deformation of the specimen. The experimental results will offer some valuable guidelines to engineering applications of the structure.