Stability Research Of Strain Hardening Cryogenic Vessels

Strain strengthen pressure vessel have the advantage such as light-duty and so on so that strengthening economy that it obtains continuous development and utilization, but its stability is worthy of discussion. This paper focus on the stability of strain strengthen pressure vessel, analyzes the influence of strain strengthening technology on internal pressure plastic stability and the outside pressure stability, and analyzes the situation of the strain strengthen pressure vessels with reinforcing ring on internal pressure plastic stability and the outside pressure stability.The main research contents and conclusions are as follows:(1) Sure the two preferences of strain strengthen pressure vessel for the stability analysis: plastic limit load and the critical buckling load; Choosing ANSYS finite element analysis software; choosing double linear analysis model for austenitic stainless steel material model; Using generalized arc-length method to solve nonlinear equations and incremental elasto-plastic finite element method to determine the plastic limit load; Using eigenvalue analysis to forecast the structure theory buckling strength, namely the buckling critical load.(2) Analysing the effect on internal pressure plastic stability of container with different variables from theory analysis, finite element numerical simulation analysis and experimental analysis three aspects, all come to the conclusion that The prestrain processing has no influence on container plastic stability.(3) Using finite element analysis the effect on the outside pressure stability with different containers prestrain variables. This paper concludes that the prestrain processing has certain effect on outside pressure stability, and the influence on different length-diameter ratio containers has some differences. When the length-diameter ratio (?)is less than (?),the relationship between (?)-C has no consistent relationship rule, the strain hardening or increase or decrease outside pressure stability. When the length-diameter ratio(?)is more than (?),the relationship between (?)-C is index of e-Bc, the strain hardening always decreases outside pressure stability of vessels.It is reasonable for controlling the length-diameter ratio (?)less than (?) while using strain strengthening technology(4) Analysis the stability of the strain strengthen pressure vessel with reinforcing ring, this paper concludes that the set mode of reinforcing ring has the obvious influence on the stability of the strain strengthen pressure vessel. While using reinforcing ring on the strain strengthen pressure vessel,it is reasonable that reinforcing rings use lap steel section,are equal spacing placed,are placed inside the cylinder body wall.