钢桥整体节点焊接残余应力三维有限元分析

Three-Dimensional Finite Element Analysis of Welding Residual Stress in Integral Panel Point of Steel Bridge

钢桥整体节点最常见的问题是焊缝处出现疲劳裂纹,焊接残余应力是重要影响因素之一。在大型有限元软件ANSYS的基础上,开发了相应的焊接程序,选用三维实体单元,考虑材料物理性能随温度和相变的影响,采用内部生热的加载方法模拟焊接热源的移动,运用单元生死技术模拟多道焊过程,获得了焊接温度场和应力场的动态变化过程,并对计算结果进行了分析。

The most common problem of the integral panel point of a steel bridge is the fatigue cracks occurring at the welding seams of the point and the welding residual stress is deemed as one of the important influential factors that causes the cracks. On the basis of the large-scale finite element software ANSYS, a corresponding welding program was developed. The internal heat generation loading method was first used to simulate the moving of the welding heat source through selecting the three-dimensional solid elements and taking into account of the physical properties of materials changing with the temperatures and phase transformation. The birth and death technique was then used to simulate the process of the multi-pass welding and the dynamic change process of the welding temperature field and stress field were obtained. Finally, the results of the calculation were analyzed.