基于三参数威布尔分布模型的超高强度抽油杆概率疲劳寿命曲线

Probabilistic fatigue life curve of ultra-high strength sucker rods based on a three-parameter Weibull distribution model

通过疲劳试验获得HL和HY两种超高强度抽油杆的疲劳数据,首次采用三参数威布尔分布,建立新的抽油杆疲劳寿命预测模型,进而拟合HL和HY两种类型超高强度抽油杆的概率疲劳寿命曲线。基于正态分布Basquin模型和三参数威布尔分布新模型进行抽油杆疲劳寿命预测。结果表明:基于三参数威布尔分布新模型计算得到的HL型、HY型抽油杆疲劳寿命与试验结果误差分别为1.25%和4.39%,基于正态分布Basquin模型疲劳寿命与试验结果误差分别为12.50%和19.84%,基于三参数威布尔分布新模型拟合精度更高。

In this study,the fatigue data of HL and HY ultra-high strength sucker rods were obtained by fatigue testing,and a new fatigue life prediction model of the sucker rod was established by using a three-parameter Weibull distribution method,and then the probabilistic fatigue life curve of the HL and HY super-high strength sucker rods were figured out.The predicted fatigue life using the new three-parameter Weibull distribution model was compared with the normal distribution Basquin model based on the experimental data.The results show that the errors of the fatigue life of the HL and HY types sucker rods calculated by the new model in comparison with the experimental data are 1.25%and 4.39%,respectively,while the errors of the Basquin model are 12.50%and 19.84%.The high accuracy of the new model based on the Weibull distribution has been verified.