盾构隧道复合管片接头板焊接的数值模拟研究

Numerical Study on Welding Deformation and Residual Stress of Composite Segment Joint Plate in Shield Tunnel

焊接变形及残余应力的存在会对焊接构件的应用产生不利影响,进行结构构件焊接变形的高精度预测和残余应力的分布预测具有重要的工程意义。本文针对复合管片接头板构件,利用ABAQUS有限元软件建立复合管片面板及接头板的三维实体模型,同时考虑材料非线性、几何非线性和边界非线性,并基于热-弹-塑性有限元法对接头板四周的焊接进行了模拟,分析了不同焊接顺序、环境温度及拘束状态对接头板焊接变形和残余应力的影响。结果表明:焊接顺序对复合管片接头板的变形有明显影响,采用平行对称焊接,先焊接长焊缝,后焊接短焊缝的顺序可有效降低Z方向的变形量;环境温度会改变构件残余应力的分布,随着环境温度的升高,纵向残余拉应力逐渐较小,距接头板上边缘约140~280 mm范围内的压应力也减小,而其他范围内的压应力呈增大趋势;拘束状态对纵向残余拉应力的影响较小,对纵向残余压应力的分布影响较大,在相距600~840 mm范围内设置两个对称拘束可对焊接变形起到控制作用。

The existence of welding deformation and residual stress will have a negative impact on the application of welding components.It is significant to predict the welding deformation and residual stress distribution of structural components with high accuracy.In this paper,a three-dimensional solid model of composite segment panel and joint plate was established by ABAQUS finite element software.And this paper also considered material nonlinearity,geometric nonlinearity and boundary nonlinearity,the welding around the joint plate was simulated based on thermo elastic plastic finite element method,and the welding deformation of butt joint plate and residual stress in different welding sequence,ambient temperature and constraint state were analyzed.The results show that the welding sequence has an obvious influence on the deformation of the composite segment joint plate.The parallel and symmetrical welding method can effectively reduce the deformation in the Z direction by welding the long weld first and then the short weld;the environmental temperature can change the distribution of the residual stress of the component.With the increase of the environmental temperature,the longitudinal residual tensile stress is gradually smaller,which is about 140~280 mm from the upper edge of the joint plate.And the compressive stress in the range of 600~840 mm also decreases,while the compressive stress in other ranges increases;the restraint state has little influence on the longitudinal residual tensile stress,and great influence on the distribution of the longitudinal residual compressive stress.Setting two symmetrical restraints in the range of 600~840 mm apart can control the welding deformation.