摘要焊接是两种或两种以上同种或异种材料通过原子或分子之间的结合和扩散连接成一体的工艺过程，焊缝是焊件经焊接后所形成的结合部分。焊接方法多种多样，但无论何种焊接方法，由于焊接时局部不均匀热输入，产生焊接应力与变形，会导致在焊接接头中产生冷、热裂纹等缺陷，还会影响焊接件的形状尺寸精度、疲劳强度和断裂特征，这直接影响到焊接结构的使用性能。因此需了解焊接热输入，掌握焊接应力与变形的规律，以更好地预防及消除焊接缺陷，提高焊接质量。本文首先分析钢板和铜板的焊接，以铝为填充材料，完成不同坡口的焊接模型创建，运用ANSYS进行有限元仿真，分析焊接接头的残余应力、变形情况及温度场分布，并根据分析结果采取合理预防措施减少焊接残余应力与变形；另外设计一个焊接结构减速器箱体，采用合理的焊接工艺以得到符合要求的箱体结构。50058

毕业论文关键词：焊缝；残余应力；温度场；箱体焊接结构

Abstract Welding is a process that could connect two or more kinds of the same or dissimilar material through the binding between atoms or molecules and the diffusion, welding line is combining part formed by welding process. Welding methods varied, but regardless of any welding method, the local heat input is uneven, producing welding stress and deformation which will result in producing cold or heat cracks and other defects in welded joints, and affect the precision of the shape and size, fatigue strength and fracture characteristics of welded parts, which will directly affects the performance of welded structures. Therefore, we need to understand the welding heat input, master the rule of welding stress and deformation, in order to prevent and remove welding defects, and improve the quality of welding better. This article analyzes the welding process of the steel plate and copper plate, using aluminum as filler material, complete the weld model creation of different grooves. I using ANSYS finite element simulation, analysis the residual stress, deformation and temperature distribution of welded joints, and take reasonable precautions to reduce the welding residual stress and deformation on the basis of analysis result. In addition, I design a welded structure reducer cabinet, using reasonable process in order to obtain a cabinet that meet the requirements.

Keywords: welding line; Residual stress; temperature field; Cabinet welded structures

目  录

第1章 绪论 1

1.1 研究背景 1

1.1.1 焊接技术的发展与现状 1

1.1.2 焊接方法 2

1.1.3 焊接接头 3

1.2 焊接应力与变形 4

1.2.1 引起焊接应力与变形的机理及影响因素 5

第2章 不同坡口焊缝的有限元分析 7

2.1 ANSYS简介 7

2.2 异种金属焊接 8

2.3 有限元模型及模拟焊接条件 9

2.3.1 物理模型 9

2.3.2 有限元模型和网格划分 12

2.3.3 焊接方法和焊缝热源的处理 12

2.4 焊缝分析过程 12

2.4.1 U形坡口的分析处理 12

2.4.2 V形坡口的分析处理 19

2.4.3 双V形坡口的分析处理 23