Strength damage behavior analysis of silicon carbide(SiC) ceramic cylindrical shells under hydrostatic pressure based on the state-based peridynamics

Ceramics are one of the most promising materials for pressure-resistant shells of submersibles due to their exceptional mechanical properties. However, ceramics are brittle materials, and the occurrence of strength damage is inevitably accompanied by the generation and propagation of cracks. A new state-based peridynamic damage model is established, the relation between critical elongation and critical energy release rate for tensile and compression fracture is deduced innovatively, to investigate the strength damage behavior of silicon carbide (SiC) cylindrical shells under hydrostatic pressure. The findings demonstrate that by increasing cylinder thickness, the structural damage pressure can be significantly improved. Moreover, the initial damage zones, are located on the internal surface of shell and induced by the compression fracture, and evenly scattered at 90 degrees around the circular direction. As pressure increases, tensile damage zones emerge on the external surface of cylinder. The failure zones on the interior and exterior walls of the shell propagate along the circumferential direction firstly, then extend toward the middle surface until the damage zones completely penetrate the entire thickness, and the cylinder loses its load-bearing capacity.