Progressive failure method and structural optimization analysis of marine sandwich L-shaped composite joints

The design and load-bearing characteristics of connection joints are the main factors restricting the load-bearing capacity of composite hull structures. In the present paper, the transition joint between the deck and the broadside of the main hull is designed and manufactured by combining bolt connection and cementing, which provides a reference for the design of large-scale composite hull structure. Based on Shokrieh-Hashin criterion and coherent zone modeling method, the simulation method of progressive failure of complex composite structures is improved and renewed. The test results show that the failure mode and ultimate load predicted by numerical method are in good agreement with the test results. Based on the numerical calculation method, the influences of the overlap width d of the hat profile and the overlap width s of the hand-pasted reinforced area on the strain, displacement and ultimate bearing capacity of the joint are quantitatively analyzed, and the optimal scheme of the full-scale deck-side joint is formed, which provides support for the design of large-scale marine composite joint.