基于损伤力学的HL级抽油杆疲劳分析研究

抽油杆在使用过程中受到损伤会对其安全性能造成影响。为分析损伤对HL级抽油杆安全性能的影响程度，根据损伤力学原理建立了抽油杆疲劳损伤演化模型，采用有效应力法与ANSYS有限元软件，对裂纹损伤、蚀坑损伤和偏磨损伤3种损伤形式下HL级抽油杆的剩余疲劳寿命进行了数值模拟。通过正交试验分析了3种损伤形式下深度、宽度、角度等影响因素对HL级抽油杆剩余疲劳寿命的影响，并利用多元回归方法得到了疲劳寿命与影响因素的关系式。模拟结果表明，3种损伤形式下影响抽油杆疲劳寿命的因素，按影响程度高低排列:裂纹损伤，依次为裂纹的位置、角度、深度和宽度；蚀坑损伤，依次为蚀坑的位置、深度和半径；偏磨损伤，依次为偏磨的位置、深度和长度。3种损伤形式下HL级抽油杆疲劳寿命与影响因素回归关系式的调整决定系数分别为82.0%、94.0%和90.9%。研究结果表明:损伤位置对HL级抽油杆疲劳寿命的影响极其显著；裂纹深度、角度，蚀坑深度和半径及偏磨深度的影响显著；裂纹宽度也有一定影响。3种损伤形式下HL级抽油杆疲劳寿命与影响因素的回归关系式，可为判断HL级抽油杆的剩余寿命提供依据。 

Fatigue Analysis of HL Rod Based on Damage Mechanics

In order to analyze the influence of a damaged HL-class sucker rod on its safety performance during the process of use, the fatigue damage evolution model of the sucker rod was established according to the principle of damage mechanics combined with the effective stress method with ANSYS finite element software to conduct numerical simulations for the residual fatigue life of HL-class sucker rod under three kinds of damages, namely crack, corrosion pit and eccentric wear. The effects of three damage influencing factors (shape, size, position, etc.) on the residual fatigue life of HL-class sucker rods were analyzed by an orthogonal test, and the relationship between the fatigue life of HL-class sucker rod and the influencing factors was determined by multiple regression method under three kinds of damages. The simulation results showed that for crack damage, the impacts on fatigue life could be listed from top to bottom as the crack position, angle, depth and width. For corrosion pit damage, the impacts listed were the pit position, depth and radius; for the eccentric wear damage, the impacts were the eccentric wear position, depth and length. The adjust decision coefficient of the regression relationship between the fatigue life of HL-class sucker rod and the influencing factors under the three kinds of damages were calculated to be 82.0%, 94.0% and 90.9%, respectively. The research results indicated that the damage position had an extremely significant effect on the fatigue life of HL-class sucker rod. The depth and angle of crack, the depth and radius of the corrosion pit, and the eccentric depth had significant effects on the fatigue life, and the crack width exhibited a certain influence. The regression relationship between the fatigue life of HL-class sucker rod and the influencing factors under three kinds of damages could provide a basis for judging the residual life of HL-class sucker rod.