Unified buckling computational framework of hydro-statically-loaded stiffened composite cylindrical shells

In this research, a unified computational framework was developed to analyze the complex multiple buckling modes of stiffened cylindrical shells under hydrostatic pressure, and avoid the complex process of calculating multiple buckling modes separately by traditional methods. The stiffener-shell displacement constraints were analyzed through introducing stress distribution to the shell. The minimum potential energy principle was adopted for the buckling load solution. The framework can predict the overall buckling, tripping, and coupled shell-stiffener buckling simultaneously, and reveal the relationship between buckling modes and structural di-mensions. The unified framework is more convenient and saves computational resources compared with the finite element method. Based on this new method, the buckling mode transition characteristics under simply-and fixed-supported boundary conditions were discussed. An energy-based criterion was proposed to evaluate the occurrence condition of each buckling mode. The research provides a reference for the design of submerged composite stiffened cylindrical shells.