铝合金加筋板焊接温度场和残余应力数值模拟

数值模拟作为一种高效可靠的技术手段，可分析焊接过程中温度场的分布情况。在数值模拟中，采用热源模型代替焊接热输入，使用热源模型是获取温度场的基础。梳理了现有的热源模型，并进行分类归纳，分析和总结了不同热源模型的特点、局限性及适用焊接场景。结果表明，高斯热源适应于焊接速度小、电弧冲击力小、焊接板材厚度不大的焊接方法；双椭球热源适用于焊接速度大、电弧冲击力大、焊接板材厚度较大的焊接方法；在大型构件的数值模拟中，采用带状分段移动热源可以大幅提升计算效率；针对焊接熔池形状复杂和焊接热输入需分成2部分的情况下，采用组合热源比单一热源得到的模拟结果更准确；对于动态特性明显的焊接过程，动态热源模型相比静态热源模型更具优势。

Effect of Al-foil addition on microstructure and temperature field of laser fusion welded joints of DP590 dual-phase steel and AZ31B magnesium alloy

As an efficient and reliable technical means, numerical simulation can effectively and comprehensively analyze the distribution of temperature field in the welding process. In the numerical simulation, the heat source model is used to replace the welding heat input, and the accurate heat source model is the basis to obtain the accurate temperature field.In this paper, the existing heat source models are sorted out, classified and summarized, and the characteristics, limitations and applicable welding scenarios of different heat source models are analyzed and summarized. Gauss heat source is suitable for welding methods with low welding speed, low arc impact force and small thickness of welding plate; Double ellipsoidal heat source is suitable for welding methods with high welding speed, large arc impact force and large thickness of welding plate; In the numerical simulation of large-scale components, the calculation efficiency can be greatly improved by using the strip segmented moving heat source; When the shape of weld pool is complex and the welding heat input needs to be divided into two parts, the simulation results obtained by using the combined heat source are more accurate than the single heat source; For the welding process with obvious dynamic characteristics, the dynamic heat source model has more advantages than the static heat source model.