Interfacial Damage Propagation of Composite Stiffened Panels Considering Type Ⅲ Fracture Energy
The significance of Type Ⅲ fracture energy in influencing damage to the stiffener-skin interface of composite stiffened panels is often disregarded.In this paper,the stiffener-skin interface damage propagation for buckled I-shaped and Ω-shaped stiffened composite panels was studied by experimental and numerical methods.The post-buckling process of two kinds of stiffened panels was analyzed by numerical simulation based on the initial criterion and the Reeder interface damage propagation criterion considering Ⅲ fracture.The buckling modes and failure forms of two types of panels were compared,and the distributions of energy release rates of each type during stiffener-skin interface damage propagation were characterized.It is concluded that,for Ω-shaped stiffened composite panels,the damage propagation of interface is mainly caused by out-plane peeling force,and the typeⅠfracture energy plays a major role in the damage initiation and propagation of the interface.For I-shaped stiffened composite panels,the damage propagation of interface is mainly caused by shear force,and the type Ⅲ fracture energy plays a dominant role in the damage propagation of the interface.The above-mentioned study elucidates the mechanisms by which various types of fracture energies operate during the process of interfacial damage propagation in composite stiffened panels.This establishes a foundation for the investigation of numerical simulation analysis methods for the post-buckling behavior of composite stiffened panels.