钢梁桥焊接残余应力的计算机模拟  

Computer Simulation of Welding Residual Stress in Steel Girder Bridge

作　　者：卫军[1] 汪东明[1] 刘晓春[1] 吴志强[1] 高宗余[2] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中铁大桥勘测设计院集团有限公司,湖北武汉430050

出　　处：《桥梁建设》2015年第4期94-99,共6页Bridge Construction

基　　金：中国铁路总公司科技研究开发计划(2013G001-A-2)~~

摘　　要：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 welding process and in accordance with the occurrence mechanism and characteristics of the welding residual stress in the steel structure, the simplified model and 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-strueture, 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 so as to simulate the process of welding heat transfer along the depth in the actual welding. By way of example of the welding of the orthotropic steel deck plate with U ribs of the Hutong Changjiang River Bridge, the finite element software 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.

关 键 词：钢梁桥 焊接残余应力 温度场 应力场 计算机模拟 基本流程 有限元法 

分 类 号：U448.36[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]