螺旋缝埋弧焊管残余应力评价方法

A Method to Assess Residual Stress of Spiral Seam Arc Weld Pipe

基于弹性力学应力分析和叠加原理,研究了螺旋缝埋弧焊管切环法残余应力测试中的残余应力分布。建立了能综合考虑管段切口张开量、轴向错位量和径向错位量等因素的新残余应力评价方法,并与应变片法残余应力测试结果进行了对比。结果表明:应变片法测试的最大残余剪切应力平均值和局部最大剪切残余应力值均与新评价方法给出的相应值接近;管段内的宏观(平均)残余应力来自管段切开后的轴向错位和周向张开量,管段内残余应力的不均匀性来自管段切开后的径向错位。存在较大的径向错位情况下,宏观最大剪应力与局部最大剪应力的极大值之间有很大差别。就管线的工程应用而言,可以局部最大剪应力的极大值作为残余应力的控制条件。

The residual stress distribution of the tangential residual stress, the hoop residual stress and the normal residual stress test of spiral seam arc weld pipe were studied on the basis of elastic mechanics analysis and superposition theorem. And the new methods taken account of pipe cut opening amount, axial displacement amount and radial displacement amount synthetically for assessing residual stress was established, and that was compared with the residual stress test result from strain -gauge method. The comparison result indicated that the mean of maximal residual shearing stress and that of partial maximal residual shearing stress using straingauge method is close to the corresponding value using new method. Also, it can be identified that the macroscopic （mean） residual stress in the pipe was caused by the axial displacement and circumferential opening amount in the pipe, while the inhomogeneity of residual stress in the pipe was caused by the radial displacement when the pipe was cut off. ff the radial displacement is wide, the difference between the maximum of maximal shearing stress and that of partial maximal shearing stress increased. As for the engineering application of pipeline, the maximum of partial maximal shearing stress can be specified as the controlling condition for residual stress.