针对焊接过程复杂的边界条件及高度非线性，基于钢结构焊接残余应力的产生机理及特点，提出钢梁桥复杂结构构造焊接残余应力的简化模型和计算机模拟的基本流程。采用热－结构单向顺序耦合的方法先进行温度场分析，后将温度场计算结果作为预定义场进行加载求解应力场，实现钢梁桥焊接残余应力的计算机模拟。基于生死单元技术采用逐步激活焊缝单元模拟焊缝材料的逐步填充过程，采取生热率的方式模拟热源的移动加载，以模拟实际焊接中沿深度方向的焊接传热过程。以沪通长江大桥正交异性钢桥面板与U 肋焊接为例，采用有限元软件ANSYS分析焊接过程中的温度与应力响应，计算结果与理论规律吻合良好，验证了所提方法和基本流程的可行性。%In view of the complex boundary conditions and high non‐linear degree of the weld‐ing process and in compliance with the occurrence mechanism and characteristics of the welding re‐sidual stress in the steel structure ,the simplified model and the basic flow of computer simulation for the welding residual stress in the constructional details of the complex structure of the steel girder bridge were proposed .By the method of one‐way sequential coupling of thermo‐structure , the temperature fields were firstly analyzed and the calculation results of the temperature fields were then taken as the predefined fields and were used to load and solve the stress fields in order to realize the computer simulation of the welding residual stress in the steel girder bridge .Based on the element birth and death technique ,the process of gradual filling of the welding materials was simulated by gradually activating the weld seam elements and the moving loading of heat source was simulated by the heat generation rate method in order to simulate the process of welding heat transfer along the depth of the actual welding .By way of example of the welding of the orthotropic steel deck plate with the U ribs of the Hutong Changjiang River Bridge ,the finite element soft‐ware ANSYS was used to analyze the temperature and stress responses of the welding process and it was found that the calculation results were quite coincident with the theoretic law ,verifying that the proposed method and basic flow were feasible .
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