基于临界距离理论预测T型管节点的疲劳强度

Prediction of fatigue strength of pipe the T-welded based on critical distance theory

依据已有支管受轴向荷载的T型焊接圆管节点的实验数据,使用ANSYS进行了有限元分析,并利用临界距离理论的点法和线法,预测了构件的疲劳强度。选取第一主应力点沿其最大梯度方向作为临界距离理论的聚焦路径。研究结果表明:预测的疲劳强度与疲劳强度实测值的误差在20%以内。临界距离理论能够在实验数据不足的情况下对焊接管节点的疲劳性能提供较精确的理论预测,为工程应用提供有价值的参考。

Based on the experimental data of the T-welded round pipe joints with the axial loads on the branch pipe,the finite element analysis is carried out by using the software ANSYS.The point method(PM)and the line method(LM)in the critical distance theory are adopted to predict the fatigue strength of the pipe joints.The maximum gradient direction of the first normal stress point is selected as the focal path of the method.The results show that the difference between the calculated values of the fatigue strength by the critical distance theory and the experimental values is in the range of±20%.With the lack of the fatigue experimental data,the critical distance theory can provide an acceptable prediction for the fatigue strength.The predicted results can be as a valuable reference for the engineering application.