自增强三维高压油管的疲劳寿命预测

Prediction of Life of Autofrettaged 3D Tube

基于弹塑性理论的自增强技术可以提高高压油管的使用寿命.对三维高压油管进行了弹塑性有限元分析,通过计算油管的残余应力,探讨了自增强技术在提高油管寿命方面的研究与应用.对不同自增强压力下的油管在工作压力作用下最大应力值进行比较,确定了最佳自增强压力.基于应力-寿命法,应用MSC.Fatigue软件对自增强前后高压油管的疲劳寿命进行预测,结果表明自增强后三维高压油管的疲劳寿命与未进行自增强处理油管的疲劳寿命分布有着明显的差异,自增强前最小疲劳寿命区位于内壁,而自增强后最小疲劳寿命区分布在壁间,自增强技术使油管最小疲劳寿命提高了5倍以上.

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.