Numerical Analysis of a Separable Metal Composite Pressure Vessel

This article presents a numerical solution to the problem of delamination in a separable Metal Composite High-Pressure Vessel (MC HPV). This problem is associated with local buckling of the inner metal shell (liner) surrounded by an outer rigid composite shell. A geometrically and physically nonlinear MC HPV deformation model is constructed considering the three-dimensional stress-strain state, real-time mode, and technological deviations inherent in real vessel designs. The model combines the deformation of the vessel end domes and the cylindrical part. A unilateral constraint is believed to exist on the interface between the liner and the composite shell, allowing the liner to delaminate from the latter when bending. Calculations are performed using the finite element method in the LS-DYNA software package in a dynamic formulation. The vessel is divided into solid finite elements such as TSHELL and SOLID. Numerical analysis of delamination is carried out for two design schemes of the separable vessel: without technological deviations and in the presence of technological deviations on the cylindrical part of the vessel. A local small-thickness gap between the liner and the composite shell is taken as a technological deviation so that the liner and the composite shell have a regular geometric shape without initial imperfections. Comparative analysis showed weak mutual influence of local bends on the end dome and the cylindrical part of the liner. Deformation of the liner end dome is of a complex nature; circumferential and radial wrinkles of local buckling appear on it in the zone of plasticity.