Buckling performance of inner corrugated pressure shells under external hydrostatic pressure

The most fundamental and central component of submarines and deep-sea space stations is the cylindrical pressure shell. In this paper, a pressure shell with inter corrugated structure was proposed to significantly improve its compression performance. 7 pressure shells including 6 inner corrugated pressure shells and 1 cylindrical pressure shell were fabricated and hydrostatic pressure tested. Geometrical deviations including thickness deviation and out-of-roundness were considered between the actual fabricated pressure shells and the ideal models. 3D scanner was used to measure the 3D contour point cloud data of all shells and the reverse modeling was performed. Nonlinear finite element analysis of reverse modeled shells containing actual geometric imperfections were performed to predict their buckling performance under external hydrostatic pressure. The results show that the corrugated structure can significantly increase the critical buckling load of the pressure shell. The failure positions of most pressure shells in the critical buckling state were mainly located near the middle region of the shell. The numerical calculation results were in good agreement with the experimental results. This research can provide good guidance for the design of pressure structures for large deep-sea equipment such as submarines and deep-sea space station.