Research on Out-of-Plane Shear Mechanical Properties of Damaged Composite T-joints

Composite materials have been widely used in the aviation field because of their light weight, large modulus and high strength. In this paper, the interface mechanical properties of composite T-joints under shear load are tested through experiments, which concluded that the ultimate load of the structure with defects is reduced from 29.01 kN to 27.40 kN and its bearing capacity is reduced by 5.5%. Then, based on the Cohesive Zone Model (CZM), a progressive damage model is established for damage failure analysis. The results show that the damage under shear load mainly extends from both sides to the center. When there is a prefabricated defect in the interface layer, the initial damage occurs near the defect and spreads to both ends of the load direction.