Stress Analysis of Pre-stressed Steel Wire Winding Ultrahigh Pressure Vessels Based on Birth and Death Element Method

Abstract

The pre-stressed steel wire winding vessel is to wrap high strength steel wire on the inner cylinder with a certain initial tension, depending on the pretension force and the elastic contraction of the winding layer, the inner cylinder produces the initial pretension force, which can counteract the circumferential stress caused by the working internal pressure, thus effectively increasing the carrying capacity and fatigue life of the vessel. In order to enhance the pretightening effect of the steel wire winding layer on the inner cylinder, it is proposed to change the slope of the inner cylinder end surface, and to process the cylinder end surface into a inclined surface, so that the pretightening height of the winding layer is higher than the height of the inner wall bearing surface, so as to ensure the better pretightening effect of the inner cylinder. Based on the finite element analysis software, considering the influence of steel wire layer friction on the prestressing effect of the cylinder and the winding process of the steel wire layer by layer, the birth and death element method is adopted. Under the design requirement of working pressure of 147 Mpa and inner diameter of 160 mm, the stress of two kinds of pre-stressed steel wire wound vessels with end structure is simulated and analyzed under pre-tension and working condition. The simulation results show that when the volume and radius of the inner cylinder are constant, the oblique end structure is used to replace the flat end structure, and the thickness of the cylinder and the number of layers of the winding steel wire can be reduced. The overall mass of the oblique end structure is about 13.94 lower than that of the flat end structure.