L485管线钢焊接接头应力状态数值模拟

Numerical Simulation of Stress State of Welded Joint of L485 Pipeline Steel

根据焊接热弹塑性理论,采用ANSYS有限元分析软件通过热-力耦合的分析方法获得L485管线钢焊接接头应力场。并采用超声波残余应力检测结果验证了模拟的准确性,分析了管道内表面和外表面的轴向应力、环向应力分布情况,并研究自然冷却(外界温度分别为5、20℃)、焊后保温、焊后热处理对L485管线钢焊接接头应力分布状态的影响规律。结果表明,自然冷却情况下,外界温度20℃的应力峰值会比外界温度5℃低9 MPa;以外界温度20℃时管线钢的焊接接头应力峰值为基准,焊后保温处理应力峰值降低25 MPa,焊后热处理应力峰值降低154 MPa。

According to the theory of welding thermo-elastoplastic,the stress field of welded joint of L485 pipeline steel was obtained through thermal mechanical coupling analysis method using ANSYS finite element analysis software.The ultrasonic residual stress test results were used to verify the accuracy of the simulation.The axial stress and circumferential stress distribution of the inner and outer surfaces of the pipe were analyzed,and the stress distribution of the welded joint of the L485 pipeline steel were studied under the natural cooling(the external temperature is 5℃and 20℃),the postweld heat preservation and the postweld heat treatment.The results show that under the condition of natural cooling,the peak stress at 20℃is 9 MPa lower than that at 5℃.Taking the peak stress at the outside temperature of 20℃as the benchmark,the peak stress after the postweld heat preservation decreases by 25 MPa,and the peak stress after postweld heat treatment reduces by 154 MPa.