摘要焊接残余应力和变形的存在严重影响焊接质量，测试工件焊后的残余应力和变形对提高焊接质量有着重要意义。本文采用小孔法对Q345钢大厚板焊接接头残余应力进行了测量，并采用ANSYS软件对焊接残余应力和变形进行有限元模拟计算，分析了三维模型计算结果和试验结果的异同，比较了二维模型和三维模型的应力分布特征。研究结果表明：二维模型和三维模型上下表面的残余应力模拟结果吻合；在接头上表面，纵向残余应力三维模型模拟结果和试验结果整体吻合；横向残余应力三维模拟结果和试验结果在焊缝区及附近吻合较好，两者均在焊趾附近出现最大拉应力。在接头下表面，纵向残余应力的三维模拟结果和试验结果在拉应力区吻合情况较好，母材部分的压应力模拟值偏小；横向残余应力数值差异较大，但应力变化趋势一致。变形的三维模拟结果与试验结果存在偏差。86152

毕业论文关键词：数值模拟；大厚板；多道焊；小孔法；残余应力和变形

Abstract Welding quality was effected by the welding residual stress and deformation seriously when thick plate was weld。Welding residual stress and deformation of the workpiece was tested to improve the quality of workpiece,which has important significance。In this paper,hole-drilling method was used to measure the residual stress of multi-pass weld of thick plates and software was used to perform the finite element analysis of welding residual stress and deformation。Differences and similarities of three-dimensional model in residual stress was coMPared with experimental results。The distribution of residual stress in two-dimensional stress model and three-dimensional model was coMPared。Studies have shown that the distribution of residual stress in two-dimensional model’s upper and lower surfaces were similar with that in three-dimensional models’。On the upper surface,the longitudinal residual stress in the three-dimensional model and the experimental results were agreement well；The transverse residual stress of the three-dimensional model in the vicinity of the weld toe zones agreed well with that in experimental results。Both of them appeared the maximum tensile stress near the weld toe zones。On the lower surface,the longitudinal residual stress in the three-dimensional model and experiment results were in good agreement in the tensile stress zone；The value of compressive stress in three-dimensional model was smaller than experimental results in parent metal。The transverse residual stress was different in value,but the tendence was consistent。Deformation in three-dimensional model and experimental results were in error。

Keywords:Numerical simulation;Large thick plate Multi-pass weld;Hole-drilling method;Residual stress and deformation

目  录

第一章 绪论 1

1。1 课题的研究背景及意义 1

1。2 厚板数值模拟研究进展 2

1。2。1 国外厚板数值模拟研究进展 2

1。2。2 国内厚板数值模拟研究进展 3

1。3 厚板多道焊数值模拟的难点 4

1。4 主要研究内容 4

第二章 材料设备和试验测量 5

2。1 材料及焊接方法 5

2。1。1 试验材料 5

2。1。2 焊接方法 5

2。2 焊接温度和变形测量 8

2。2。1 焊接温度测量 9