Abstract:Based on elastic-plastic theory,autofrettage technology can improve the life of tube with high-pressure.The residual stress of three-dimensional tube was obtained via an elastic-plastic finite element analysis,research and application on how to improve life of tube by autofrettage technology was discussed.Through comparing the maximum stress of the tube under different levels of autofrettaged pressure,the best level was determined.Based upon the prediction of stress-life methods,a prediction of life of tube was conducted using MSC.Fatigue package.Results show that after autofrettage of three-dimensional tube,the life has an obviously different distribution,the region of the lowest life lies in inner of tube before it is autofrettaged,but the region of the lowest life moves between inner and outer of tube after it is autofrettaged,autofrettage technology makes the lowest life of tube increase more than quintupling.
