某输气管线穿越段应力分析

Stress Analysis of a Gas Pipeline Crossing Section

某管线水域穿越段测绘发现其弹性敷设曲率半径为600 D,不满足标准要求,采用理论计算和数值模拟对该管段进行应力分析。计算发现,设计压力下该段管道环向应力和当量应力满足标准要求,但轴向应力不满足要求,其安全系数由标准要求的2.5降低为1.71。轴向应力过高由弹性敷设曲率半径过小造成,不能通过降低运行压力的方式使轴向应力满足要求。设计压力下弹性敷设曲率半径至少应为996 D,才能使轴向应力满足标准要求。

It was found that the elastic laying curvature radius of a pipeline crossing section in a water area is 600 D,which did not meet the standard requirements.Stress analysis of the pipe segment was carried out by using theoretical calcution and numerical simulation.The calculated results showed that the hoop stress and equivalent stress under the design pressure meet the standard requirements,except axial stress.The safety factor of axial stress is reduced from the required 2.5 to 1.71.The excessive axial stress is caused by the very small elastic laying curvature radius,which cannot be reduced by reducing pipeline operating pressure.The curvature radius of elastic laying should be at least 996 D to make the axial stress meet the standard requirements under pipeline design pressure.