Objectives In order to effectively evaluate the safety and integrity of buoyancy material integrated structures in underwater vehicle under service conditions in deep water, the generation and propagation of debonding at the interface between steel and buoyancy materials were studied using experimental and simulation methods.

Methods  First, the mechanical parameters of the material interface are measured through standard tests and numerical calibration, and a cohesive contact model for stimulating interface failure is constructed. Then, based on finite element simulation, regions of high stress gradients and locations prone to damage are estimated through global stress/deformation analysis, and the expansion path and mode of debonding are determined through submodel simulation.

Results  Interface debonding tends to occur at the top of the circumferential partition frame within the integrated structure, mainly in I-type, extending along the circumferential direction and towards the outer surface.

Conclusions  Simulation analysis reveals the interface failure position and evolution, providing a basis for simulating interface failure under complex working conditions and optimizing interface performance in the future.