摘 要

当今世界，汽车工业快速发展。车身链接作为驾驶安全的一大重要影响因素，其发展也伴随着汽车的发展不断进步。电阻点焊作为白车身焊接的主要连接方式，在汽车制造业中应用得特别广泛，因其具有生产量大、高速、低耗等优点，在汽车车身零部件的连接中使用较多。尽管点焊作为汽车车身的主要焊接方式，但在汽车制造中也存在一些问题。比如焊接试验周期长，焊接工艺制定繁琐，试验费用高，焊接质量难以保证等。为了更好地解决此类问题，一些焊接仿真模拟软件相继出现。SORPAS作为一款电阻焊领域专业的CAE仿真模拟优化软件，具备诸多优点，对汽车车身焊接的优化尤为重要，在使用中占据了重要地位。

据统计一辆白车身上焊点数量高达4000-6000个，90%的焊接都由点焊来完成，因此保证焊点强度是保证车身质量的关键。焊点强度受到很多因素影响，比如焊接电流电压、焊接时间、电极压力、材料性能等，这些因素往往是交互作用、交互影响的。本论文通过对各个因素的分类与了解，运用控制变量法及SORPAS软件，尽可能考虑到影响焊点强度的所有因素，对点焊过程进行模拟仿真，其间不停的改变各个影响参数，观察、总结各个因素是如何影响焊点强度的，根据软件输出结果分析怎么样的工况该用怎么样的焊接参数才能提高焊点强度。本论文对等厚度材料、非等厚度材料、焊接三大参数及镀层材料分别进行了模拟分析，找出了其对应的焊接问题，并用SORPAS软件进行了优化处理，然后对模拟结果进行实验验证，即收集试片，按照SORPAS模拟出的参数对相应的试片进行点焊，最后对试片进行撕裂试验，统计撕裂结果，总结SORPAS模拟结果的准确性。

关键词：电阻点焊；焊接参数；焊点强度；SORPAS

Abstract

In today's World, the automobile industries develop rapidly. With the development of automobile industry, people also more and more attach great importance to the economy and the concept of security. body connection is one of the important influence factors of driving safety, it’s development is accompanied by the development of automobile manufacturing. Welding as the main way of connection of the white body, has been widely used in automobile manufacturing, Especially for spot welding, with the advantages of large quantity, high speed, low cost and so on, spot welding is widely used in auto body parts in connection. Although welding is the main connection of car bodies, the welding itself in automobile manufacturing has a few problems. For examples, the Welding test cycle is long, the welding process is complicated, the cost of the test is high, the quality of welding is difficult to guarantee. In order to solve such problems better, some welding simulation software appeared. SORPAS as a professional CAE simulation software in welding field, has many advantages, it is very important for the optimization of car body welding, and SORPAS occupied the main status in use.

There are approximately 4000 to 6000 joints in a typical BIW, the 90% of welding is completed by spot-welding, thus ensuring the quality of resistance spot welding is the key to ensure BIW welding quality. The quality of solder joints is influenced by many factors, such as welding current and voltage, welding time, the electrode pressure, material properties, etc. These factors always effect each other interactively. The purpose of this paper is that use the SORPAS software, as far as possible to take all factors into account which affect the joint strength, to simulate the spot welding process, during which constantly change impact of various parameters, and observe, summarize that how various factors affect the joint strength, How kind of condition with how this kind of welding parameters in order to improve joint strength based on the output of the analysis software. In this paper, the thickness of the material, the three welding parameters, and coating materials are simulated analysis to identify the corresponding welding problems and then optimize the results until them meet the production requirements. Finanly according to the simulation parameters of SORPAS, weld the respective specimens. At last, tear the specimens and summarize the results to approve the accuracy of simulation of SORPAS.

Key Words：spot welding；welding parameters；Weld strength；SORPAS

目 录

摘 要 I

Abstract II

目 录 III

第1章 绪论 1

1.1 研究背景 1

1.2 研究方法 2

1.3 电阻点焊过程数值模拟应用及现状 4

1.3.1 电阻点焊在汽车工业中的应用 4

1.3.2 数值模拟在电阻点焊中的应用 4

1.3.3 电阻点焊数值模拟研究现状 5

1.4 研究内容和意义 5

第2章 电阻点焊焊点强度影响因素分析 7

2.1 电阻点焊 7

2.1.1 点焊基本原理 7

2.1.2 点焊一般工艺 8

2.2 点焊质量 8

2.2.1 焊接飞溅 8

2.2.2 影响焊点质量的因素 8

2.3 研究内容及依据 10

第3章 SORPAS介绍 12

3.1 SORPAS简介 12

3.2 SORPAS点焊模拟的输入 12

3.3 SORPAS点焊模拟的输出 13

第4章 SORPAS点焊建模与分析 15

4.1 等厚度材料点焊模拟及工艺优化 15

4.2 非等厚度材料点焊模拟及工艺优化 17

4.2.1 不等厚板材点焊的应用现状及问题 17

4.2.2 SORPAS对不等厚板材点焊的模拟及工艺分析 18

4.2.3 改善熔核偏移的研究 22

4.3 多层点焊模拟及工艺优化 25

4.3.1 总厚度相同搭接层数不同的点焊工艺分析 25

4.3.2 不同搭接方式对焊接效果的影响 26

4.4 点焊参数对熔核尺寸的影响 27

4.4.1 焊接电流 27

4.4.2 焊接时间 28

4.4.3 电极压力 30

4.5 镀层钢板点焊模拟 31

第5章 试验验证与结果分析 33

5.1 试验材料及设备 33

5.1.1 点焊设备 33

5.1.2 试验材料 35

5.2 SORPAS优化工艺实验验证及分析 35

5.2.1 等厚度材料点焊实验验证 36

5.2.2 不等厚度材料点焊实验验证 37

5.2.3 多层点焊实验验证 38

5.3 点焊参数影响实验验证及分析 39

5.3.1 焊接电流对熔核尺寸大小影响实验验证 39

5.3.2 焊接时间对熔核尺寸大小影响实验验证 40

5.3.3 电极压力对熔核尺寸大小影响实验验证 41

5.4 SORPAS模拟结果误差分析 42

第6章 结论 44

参考文献 45

附录A 模拟及试片安排 47

附录B 实验结果汇总 48

致 谢 49