Study on buckling of thin-walled composite cylinder under C-SS boundary condition

Abstract

Abstract The spigot is a common connecting method for composite containers with thin walls. The fixture is closer to the thin-walled cylindrical shell with one end clamped and one end supported (C-SS) than the boundary conditions of typical pressure vessels, which are supported (SS-SS) or clamped (C-C) at both ends. Under the boundary condition, there are very few calculations and experimental research. A buckling model of the thin-walled composite vessel was built, and the critical load was determined using the energy technique and the classical thin-walled theory. Using nonlinear numerical analysis and FEM, the buckling mode was simulated. Numerical examples were used to examine the impacts of the spigot’s length, boundary conditions, layup thickness, and sequencing on the critical load. The findings indicate that a shorter spigot, a thicker layup, and a small-angle layer closer to the center all increase the critical load. The boundary conditions of SS-SS, C-S, and C-C experienced increasing critical loads in that order; the latter was around 1.5~2 times more than the former. Ultimately, external pressure tests were used to evaluate the buckling critical loads of two distinct laminated thin-walled composite vessels, confirming the correctness of both the FEM results and the theoretical model. The variance for the former was 15%, while the latter was 8%. The findings can serve as guidelines for designing interference and winding pre-stress spigots and the structural stability study of thin-walled composite vessels.