The Research Of Autofrettage Mechanism In Ultra-High Pressure Thick-walled Vessel

Based on analyzing and discussing the overview of ultra-high pressure vessel and the development of autofrettage technology in abroad and domestic,ultra-high pressure autofrettaged vessel's stress formula of the the elastic-perfectly plastic material model, strain hardening material model and considering the Bauschinger effect material model were overviewed more comprehensive, and the thick-walled cylinder thermal stress'estimation method was introduced.Thick-walled cylinder's optimal design model was built through the 'optimization" design method, and its optimal design program was compiled by MATLAB software.Based on the thick-walled cylinder's best stress, the optimal design humane-machine interface of thick-walled cylinder was developed.This program has the man-machine dialogue function, optimal results were obtained on condition that the initial structural parameters were entered, the operating parameters in the running program interface were selected and the optimal design button was pressed.In addition,the program has the function of calculating specific point stress showing stress distribution and checking strength. It has faster computation, convergence speed, and more visual reliable accurate results, and stronger visualization function than the determination method of the elastic-plastic interface radius in the past, moreover the results is easier to store and compare.Ultra-high pressure autofrettaged vessel's stress was analysed by using the finite element method. With analytical tool of ANSYS software, the reactor's stress of not autofrettage processed and autofrettage processed were comparatived and thermal stress were analysed. The advantages of ultra-high pressure autofrettaged vessel were verified, for example higher elasticity carrying capacity, lower mean stress and cyclic stress amplitude, more uniform stress along the thickness direction, higher material utilization and so on. In addition, the inner heating thick-walled cylinder's wall stress can be reduced and the cylinder's stress is more uniform. The finite element method has higher analysis efficiency, wider analysis range and more intuitive than manual analysis in the past.According to be compared the finite element method and'optimization'design method to traditional design methods, the results were more accurate and closer to realistic value, and the analysis scope were broader. Base on being applied computer aided design technology, the program was designed, and the stress was analysed. Aimed at thick-walled autofrettaged cylinder and the conclusion are closer to actual working condition by using the finite element method. A part of autofrettage theory was verified.Figure 39 Table 6 Reference 60...