基于ANSYS的AZ31B DE-GMAW数值模拟

发布时间：2018-04-04 23:37

  本文选题：AZ31B镁合金　切入点：DE-GMAW焊接　出处：《南昌大学》2015年硕士论文

【摘要】：焊接作为一种可靠的材料连接技术,广泛应用于众多工业领域,在社会经济持续发展中发挥着重要作用。近年来,随着制造业的不断发展,传统的焊接方法越来越难以满足高质高效的生产要求,许多高效焊接方法陆续被提出来,双电极气体保护焊接方法就是其中之一,简称为DE-GMAW(Double-electrode gas metal arc welding)。本文中采用焊接温度场以及应力场的有限元分析理论,以AZ31B镁合金作为实验材料,在此基础上对这种新型的焊接工艺进行数值模拟,研究DE-GMAW焊接旁路电弧的热效率、焊件温度场以及应力场的分布规律,有助于优化DE-GMAW焊接工艺参数。首先,本文中采用熔池图像采集系统获取AZ31B镁合金DE-GMAW焊接熔池图像,经过VC++软件对图像处理后得到熔池尺寸。其次,采用ANSYS软件建立适用于AZ31B镁合金DE-GMAW焊接的复合热源模型以及有限元模型,对其温度场进行数值模拟,根据熔池尺寸的实验值和模拟值确定旁路电弧热效率的取值范围。讨论DE-GMAW焊接旁路电流对熔池尺寸以及母材热输入的影响,模拟结果与实验基本一致,验证了所建立模型以及热源作用模式的正确性。最后,使用间接耦合法,利用ANSYS软件计算AZ31B镁合金DE-GMAW焊接应力场,研究焊件动态应力发展与残余应力分布,模拟结果与焊接理论符合;探讨DE-GMAW焊接速度和电流影响焊件残余应力的规律;探索AZ31B薄板DE-GMAW焊中,不同焊件初始温度对残余应力的影响,得到焊件初始温度在50-100℃范围内可以有效地降低其残余应力。
[Abstract]:As a reliable material connection technology, welding is widely used in many industrial fields and plays an important role in the sustainable development of social economy.In recent years, with the continuous development of manufacturing industry, traditional welding methods are more and more difficult to meet the requirements of high quality and high efficiency production. Many efficient welding methods have been put forward one after another, one of which is two-electrode gas shielded welding method.Referred to as DE-GMAW(Double-electrode gas metal arc welding.In this paper, the finite element analysis theory of welding temperature field and stress field is adopted, and AZ31B magnesium alloy is used as experimental material. On this basis, the numerical simulation of this new welding process is carried out, and the thermal efficiency of bypass arc in DE-GMAW welding is studied.The distribution of temperature field and stress field is helpful to optimize DE-GMAW welding process parameters.Firstly, the weld pool image of AZ31B magnesium alloy DE-GMAW welding was obtained by using the weld pool image acquisition system, and the weld pool size was obtained after processing the image by VC software.Secondly, the composite heat source model and finite element model for DE-GMAW welding of AZ31B magnesium alloy are established by ANSYS software. The temperature field is numerically simulated, and the range of thermal efficiency of by-pass arc is determined according to the experimental value and simulation value of weld pool size.The influence of DE-GMAW welding bypass current on the size of molten pool and the heat input of base metal is discussed. The simulation results are in good agreement with the experimental results, and the correctness of the established model and the heat source action mode are verified.Finally, the indirect coupling method is used to calculate the stress field of DE-GMAW welding of AZ31B magnesium alloy by ANSYS software. The dynamic stress development and residual stress distribution of the welded parts are studied. The simulation results are in agreement with the welding theory.The influence of DE-GMAW welding speed and current on residual stress of welding piece is discussed, and the influence of different initial temperature on residual stress in DE-GMAW welding of AZ31B sheet is explored. It is concluded that the initial temperature of welding piece can effectively reduce the residual stress in the range of 50-100 鈩，

本文编号：1712244