基于SYSWELD的7A52铝合金双丝MIG焊残余应力分析-材料加工工程专业论文.docxVIP

摘 要 7A52 铝合金是一种高强装甲铝合金，在焊接构件中受焊接残余应力的影响而使 其应用受到限制，所以研究铝合金残余应力对于扩大铝合金的应用范围非常重要。 采用有限元分析方法对 7A52 铝合金焊接残余应力进行数值模拟，在节时省力的基础 上对于掌握铝合金的残余应力分布规律和改善接头性能有重大意义。 查阅文献并利用 Jmatpro 软件，得到了 7A52 铝合金部分热物理参数，初步建立 了 7A52 铝合金的材料数据库。针对双丝 MIG 焊焊接特点，考虑到双丝焊双热源加 载现象，通过利用 SYSWELD 软件本身特点分别校核了两个双椭球热源模型，通过 设置加载时间差使两个热源先后加载到焊缝上，实现了双丝焊“双热源”的特点， 不需要编写程序，灵活性强，可以推广到多丝焊热源模型的建立中去。 针对 7A52 铝合金焊接残余应力使铝合金应用受限及双丝焊热源模型建立困难等 问题，利用焊接专用有限元分析软件 SYSWELD 及其前处理环境 Visual-Environment 模拟计算了 7A52 铝合金对接接头双丝 MIG 焊温度场及残余应力场。温度场结果显 示出了两个热源加载时间不同产生的起焊和焊接结束时快速升温和降温现象。应力 场结果显示沿焊缝宽度方向的纵向残余应力出现典型的“双峰”现象，沿焊缝长度 方向的横向残余应力呈现两端受压中间受拉的分布状态。 利用盲孔法实测了焊缝方向和垂直焊缝方向的残余应力，验证了模拟结果的准 确性，证实所建热源模型的可靠性，对于利用 SYSWELD 软件进一步分析多丝焊热 源模型奠定了良好基础。 关键词：7A52 铝合金；SYSWELD；残余应力 I Abstract The application of 7A52 aluminum alloy, a kind of high-strength armor aluminum, is limited for its welding residual stress in welding components. Therefore, the research on residual stress of aluminum is rather important to expand the scope of application of aluminum. The finite element analysis methods used to simulate the residual stress of 7A52 aluminum alloy welding joint has great significance for mastering the residual stress distribution and improving joint performance of aluminum alloy on the basis of saving time and effort. The material database of 7A52 aluminum alloy was initially established by consulting literature and using Jmatpro software to get parts of thermal physical parameters of 7A52 aluminum alloy. Two double ellipsoid heat source models were established and checked by using the characteristics of SYSWELD itself taking into account of the heat load phenomenon and welding characteristics of TANDEM welding. The TANDEM welding feature of two heat sources successively loading onto the weld and double source was achieved by setting the loading time difference, which was flexible and without programming. Furthermore, it can be extended to a multi-wire welding heat source model. The welding temperature field and residual stress field of 7A52 aluminum alloy