A simulation analysis method for strength and fatigue design of prestressed wound ultra-high pressure vessels

Pre-stressed steel wire-wound ultra-high-pressure vessels (PSWUPV) are commonly used in engineering to transport ultra-high-pressure media. However, the complex structure of these containers and the frequent pressure changes pose challenges in designing their structural and fatigue strength. Three simulation design methods were compared and analyzed: the two-dimensional force method, the two-dimensional cooling method, and the three-dimensional force method. The results showed that all three methods met the stress analysis requirements. The three-dimensional surface mass force method was chosen as the preferred method for engineering applications, specifically for the process of steel wire-winding loaded with mass force. The combined load case method was used to examine the influence of steel wires on the stress of the thick-walled cylinder when wound layer-by-layer. The study also focused on the changes in stress relaxation within the steel wire layer. The results demonstrated that the residual stresses of the core cylinder and the winding layer exhibited quasi-linear superposition during the winding and preloading process. The preloading effect of the steel wire weakened with increasing friction coefficient. Simulation results showed larger errors with excessively large or small normal stiffness coefficients. Based on theoretical solutions and verification studies, the optimal friction and normal stiffness coefficients were determined to be 0.02 and 1, respectively. By achieving a reasonable distribution of residual stress in the thick-walled cylinder of the ultra-high-pressure vessel through fatigue analysis, the fatigue life of the cylinder was significantly improved.