Finite Element Simulation And Residual Stress Analysis In Autofrettage Process To GYF300 Type Ultrahigh Pressure Vessle's Thick Cylinder

The ultrahigh pressure vessel is working under very high pressure and stress. Therefore the determining factor of the design and structure's choice is whether the operation can assure long-term, stable and security. The massive research indicated that the autofrettage technology can well improve the stress distribution along thick cylinder of the ultrahigh pressure vessel and raise the elastic bearing capacity. Then it is always the main content to calculate the residual stress from autofrettage process for studying ultrahigh pressure vessel.Looking from the domestic present research situation, the computation for residual stress from autofrettage process generally uses the numerical formula computation. These methods bring a lot of work and bad precision. Therefore finite element introduction to analyze the residual stress from autofrettage process appears very important.In this article, taking the GYF300 ultrahigh voltage quartz thick cylinder which produces by the Inner Mongolia north heavy industries group corporation as the research object, and taking large-scale CAE software ANSYS as the tool, the elastic stress distribution under work load function, the residual stress and strain distribution from autofrettage process, thermal stress distribution are analyzed detailed. And finally the total stress distribution under actual work condition is computed which are done separately from after autofrettage process and not.The thick cylinder is the main load bearing part and center part of the ultrahigh pressure vessel. In order to improve the stress distribution along the thick cylinder wall and enhances elastic bearing capacity of the thick cylinder, autofrettage technology is applied to the thick cylinder. In the autofrettage process considering the plane head's machine-finishing is relatively easy, the finite element model is established to the thick cylinder with plane head. Simultaneously the model was simplified to be two-dimensional model for its axial symmetry characteristic. And the contrast between the result which are computed by finite element method and the formula numerical method confirmed the simulation of the autofrettage process is right.This ultrahigh pressure quartz cauldron is heated outside. The thermal stress has the adverse effect to the thick cylinder's stress distribution. So it is necessary to analyze detailed the temperature and the thermal stress distribution along the thick cylinder of the GYF300 ultrahigh pressure quartz cauldron. In this paper the finite element is established to do the analysis with the ANSYS hot coupling module.Finally considering each stress combined action under practical work condition, the value and the distribution of the total stress before and after autofrettage process along the thick cylinder wall of the GYF300 ultrahigh pressure quartz cauldron. The analysis and computation in this paper provide the cooperation a substratum for autofrettaging to ultrahigh pressure vessel, evaluating the ultrahigh pressure vessel's fatigue life and designing the higher ultrahigh voltage vessel in theoretically.