Research On Structural Strength And Fatigue Properties Of Ultra-high Pressure Sterilization Cylinder

Food ultra-high pressure sterilization is a new and efficient food processing method with good application prospects.According to different types of food,the working pressure range is 150MPa-700MPa,and there are frequent loading and unloading processes.Therefore,pressure vessels are required.It has extremely high load carrying capacity and high fatigue resistance.This paper systematically analyzes the ultimate pressure bearing performance and fatigue resistance of various typical ultra-high pressure sterilization cylinder structures,including self-reinforcing cylinder,wire-wound cylinder and double-layer shrink sleeve.Numerical simulation analysis.The topic has high theoretical research value and extensive engineering application background.On the basis of extensive review and careful analysis of relevant literature at home and abroad,the author has carried out the following research on the weak links of current research;(1)Theoretical analysis and numerical simulation studies are carried out for the ultimate bearing capacity of the self-reinforcing cylinder,revealing the mechanism that the self-reinforcing technology can effectively improve the ultimate bearing capacity of the cylinder structure,aiming at the minimum synthetic equivalent stress,including Self-enhancing optimization parameters including optimal super-strain.Through the comparison of simulation results and theoretical analytical solutions,the effects of material hardening and Bauschinger effect on self-enhancement are analyzed.(2)A simulation study on self-reinforcing and improving the fatigue characteristics of the cylinder was carried out.The user subroutine UMAT of material failure criterion based on plastic strain accumulation was developed.The Abaqus software was used to analyze the effect of self-reinforced residual stress on crack initiation.Based on the crack propagation module in Fatigue software,the influence of self-enhancement parameters such as super-strain and working pressure on the crack propagation life is simulated.(3)Theoretical analysis and numerical simulation are carried out for the ultimate bearing capacity of the wound cylinder.Through the theoretical analysis,several optimization parameters including the inner and outer diameters of the wound layer and the pre-tightening force are obtained.The comparison between the theoretical and simulation results is verified.On the basis of the correctness of the simulation model,the effects of different winding sections were compared,and the optimized winding section was determined.(4)Theoretical analysis and numerical simulation are carried out for the ultimate bearing capacity of the double-sleeve sleeve structure.The correctness of the theory and simulation method is verified by the comparison between the two,and the interference and the ratio of the inner and outer cylinders are obtained.Optimization parameters within.The stress distribution law and bearing capacity level of self-reinforcing cylinder,wire-wound cylinder and double-layer shrink sleeve are compared comprehensively,which provides reference for selecting suitable structure according to work requirements.