Experimental behavior and shear bearing capacity simulation of stiffened composite panels subjected to invisible damage impact

In this paper, the carbon fiber composite stiffened panel is taken as the research object, and a mechanical simulation model including shear failure is established based on the progressive damage theory of composite materials and the theory of adhesive interface degradation. The effects of discrete low-velocity impact damage on buckling stability, ultimate bearing capacity and failure mode of stiffened panels are investigated by means of tests and finite element analysis. The invisible damage was introduced sequentially to three different locations of the stiffened panel using a drop hammer impact. It was found that the damage of matrix and fiber caused by low-velocity impact may lead to the change of stiffness and strength of the structure.