【摘要】 [目的]为预判该试验设施在建造过程中的焊接变形及残余应力分布，对某空泡水洞分段结构进行了三维有限元数值仿真研究。[方法]采用分段移动热源、“生死单元法”、壳-体单元混合建模等技术，显著降低空泡水洞焊接仿真的计算量，提高非线性分析的收敛性，最终获得筒体结构的焊接变形及残余应力分布规律。[结果]结果表明，空泡水洞的筒体焊接变形主要表现为垂直焊缝方向的收缩变形和筒体截面的径向变形。[结论]通过对焊接温度场及应力场的分析，揭示了筒体焊接变形产生的机理，对空泡水洞实际建造工艺具有重要的指导意义。更多还原

【Abstract】 [Purpose] In order to predict the welding distortion and residual stress distributions of the cavitation tunnel induced in the construction process, three-dimensional finite element analysis is carried out for a segmented structure of the cavitation tunnel. [Method] Technologies of segmented heat source,birth-death element, shell-solid mixed finite element are adopted to reduce the calculation cost and improve the convergence related to nonlinearity. Then, the concerned distributions of distortion and residual stress in the structure are obtained. [Result] Results showed that the welding distortion mainly appear as the shrinking deformation which is perpendicular to the weld line, and the radial deformation of the cross-section. [Conclusion] Based on the temperature field and stress field, mechanisms of the welding distortion are dealt with, which may provide significant insights for the practical construction of the cavitation tunnel.更多还原