不同内压作用下连续管疲劳寿命有限元分析

Finite Element Analysis of Coiled Tubing Fatigue Life under Different Internal Pressure

为了弥补理论计算难以准确预测连续管疲劳寿命的不足,用ANSYS Workbench有限元分析软件建立了工作状态的连续管三维有限元力学分析模型,给出了连续管疲劳寿命有限元分析步骤,分析了不同内压作用下连续管的疲劳寿命,考察了壁厚对连续管疲劳寿命的影响,并与之前文献通过试验方法得到的结果进行比较。研究结果表明:不同内压作用下,不同壁厚连续管疲劳寿命有限元软件计算结果与试验结果趋势相同,最大误差小于8.46%,平均误差5.84%~7.04%,满足工程精度要求,可以采用有限元方法进行连续管疲劳寿命分析;增加壁厚不仅可以增加连续管的强度,还可以延长其疲劳寿命。

In order to make up the theoretical calculation defect on accurately predicting the fatigue life of coiled tubing,ANSYS Workbench finite element analysis software is used to establish the three-dimensional finite element mechanical model of coiled tubing at working condition. The finite element analysis steps of coiled tubing fatigue life is attained to analyze the fatigue life of coiled tubing under different internal pressures and investigate the influence of wall thickness on the fatigue life of coiled tubing,and the analysis result was compared with the experimental results obtained by the previous paper. The results of the investigation show that,the calculated results have the same trend as the experimental results of the coiled tubing with different wall thickness and under different internal pressure. The maximum error is less than 8. 46% and the average error is 5. 84% ~ 7. 04%,which can meet the requirement of engineering precision,verifying that finite element method could be used for coiled tubing fatigue life analysis. The increase of the wall thickness can not only increase the strength of the coiled tubing but also prolong its fatigue life.