Mechanical Properties Test and Failure Analysis of Composite Foam Sandwich Structure in Ramp-Down Zone

The method of combining test and simulation was adopted to explore the failure process and load distribution of the structure under axial compression load. The failure mode of the inclined sandwich structure was investigated by experiments. Hashin criterion and cohesive force element were introduced to establish finite element analysis model for damage simulation. The results showed that the root edge was the maximum stress area of the sandwich structure. The initial damage appeared in the bonding layer at the sharp corner of the root, and gradually expanded at the adhesion between the bottom panel and the foam, resulting in the stiffness of the lower panel plummeting and breaking.