摘要熔化极气体保护焊(GMAW)具有高效、生产成本低、自动化程度较高等优点，是现阶段应用较广泛的一类电弧焊方法。本文基于流体力学软件FLUENT，开展GMAW双丝焊焊接过程的数值分析研究，其中主要针对焊接过程中电弧行为进行数值研究，通过改变焊接电流和双丝间距，深入阐释了不同焊接参数对焊接过程的影响机理，以期为实际生产焊接工艺的制定提供理论指导与参考。

    根据流体力学中的质量连续、动量守恒、能量守恒方程，建立二维的单丝和双丝电弧模型。双丝焊中，研究了焊接电流、双丝间距情况对电弧行为的影响规律。经数值模拟研究发现，当焊接电流增大时，GMAW双丝焊电弧温度和工件表面压强峰值随之增大，电弧偏离焊丝中心轴线的角度也会增大，电弧形态由束状向球状变化。当双丝间距增大时，电弧形态由单电弧向双电弧转变，压强基本上是均匀分布的；当间距达到一定大小时，基本保持不变，而工件表面压强峰值随之先减小后增大。随着电流的增大，GMAW单丝焊电弧温度及压强变化梯度逐渐增加，电弧形状由圆柱状逐渐向两边延伸；其温度及压强变化梯度相对GMAW双丝焊较大，电弧形态均是相对轴线对称。86598

毕业论文关键字：GMAW,数值模拟，焊接电弧，双丝焊

Abstract Gas metal arc welding (GMAW) has high degree of automation, high efficiency, low production costs advantages, etc。, is a stage of the widely used class of arc welding methods。 Based on fluid dynamics software FLUENT, carry double wire GMAW  process numerical analysis and research, which focuses on welding arc behavior in the process of numerical research , by changing the welding current and double wire spacing, further explains the mechanism of the influence of different welding parameters on the welding process, with a view to developing the actual production of the welding process to provide theoretical guidance and reference。

According to the fluid mechanics quality of continuous, momentum conservation , energy conservation equation, two-dimensional single and double wire arc model is set up。Double wire welding, the welding current is studied, the influence of double wire spacing for arc behavior patterns。 By numerical simulation,the study found that when the welding current increases, the peak arc temperature and surface pressure value increases,  axis deviation wire arc angle also increases。 When the double wire spacing increases, the arc shape from single to double arc, the arc pressure is substantially uniformly distributed; when the distance reaches a certain size, basic remains the same, while the peak of the peak surface pressure decreases and then followed increases。As the current increases,arc GMAW monofilament welding temperature and pressure gradient increased gradually, the arc extending from the cylindrical shape gradually to both sides; the temperature and the pressure gradient is relatively large double wire GMAW welding, arc shape are relatively axis symmetry。

Key words:GMAW,the numerical simulation,the welding arc,double wire welding

目录

第一章 绪论 1

1。1 课题背景 1

1。2 GMAW国内外研究现状及发展趋势 2

1。3 GMAW焊接技术 3

1。3。1 缆式焊丝GMAW国内外研究现状 4

1。4 双丝焊技术 5

1。5 研究内容 7

第二章 FLUENT软件及电弧物理模型建立分析 8

2。1 FLUENT软件和UDS概述