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环形薄壁焊接结构在生产实践中有着广泛的应用。在现行工艺条件下统计火焰筒衬套组件焊接变形基本规律。并采用有限元分析软件ANSYS模拟火焰筒衬套组件焊接过程,模拟马鞍与内环焊接过程的温度场及变形情况;模拟结果表明:径向最大变形为0.494mm,而在其对应的180°处变形为0.756mm。通过理论计算,内环与马鞍焊接后径向最大变形为1.25mm,与实际焊后测量结果相符。总结模拟变形规律,为控制焊接变形措施提供理论依据。 相似文献
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分析了管类件定径挤压成形工艺,借助于有限元软件Deform-3D平台,对不同参数组合的45^#管类件定径挤压工艺进行了有限元数值模拟。给出了成形极限范围和不同参数对极限变形程度的影响规律。 相似文献
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为有效控制钢结构焊件的不均匀膨胀和收缩而造成的焊接变形,就焊接变形的主要影响因素进行分析,并简要论述了最新的变形预测方法,提出相应的矫正措施。采用火焰矫正法对大型钢构件进行矫正,在材质为低碳钢情况下控制高、中、低温矫正的温度和介质。对不同变形的部位使用相应的施工方法。 相似文献
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采用热弹塑性有限元方法开展了甲板分段焊接数值仿真,基于三维Shell单元和双椭球焊接热源模型获得了结构温度变化和应力场,得到了甲板分段焊接变形及残余应力分布特点,同时探究了纵向和横向型材15种焊接装配顺序以及3种甲板分段拘束形式对残余应力和焊接变形的影响规律。结果表明,所设计的对称交替焊接方法对应的焊接变形最小,即先从船舯向舷侧焊接纵骨,再从中间向两端交替焊接横向桁材,最后从船舯向舷侧焊接纵向桁材;在甲板分段边缘和中心施加压条约束可获得变形控制与工作量的最佳平衡;通过优化焊接顺序和约束方式,可有效实现大型甲板焊接精度控制。 相似文献
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随着新型焊接工艺被广泛应用于生产之中,其受关注度与日俱增。本文从对机械焊接技术的介绍出发,立足于机械焊接新工艺的探索,这对于机械焊接新工艺的广泛应用具有现实的指导意义。 相似文献
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Jun Li Jian-guo Yang Hai-long Li De-jun Yan Hong-yuan Fang 《Frontiers of Materials Science in China》2009,3(1):84-88
In this paper, the welding residual distortion of aluminum alloy thin plates is predicted using the elasticity-plasticity
finite element method (FEM). The factors contributing to the welding buckling distortion of thin plates are studied by investigating
the formation and evolution process of welding stresses. Results of experiments and numerical simulations show that the buckling
appearance of thin-plate aluminum alloy weldments is asymmetrical in the welding length direction, and the maximum longitudinal
deflection appears at the position a certain distance from the middle point of the side edge towards the arc-starting end.
The angular deformation direction of thin-plate weldments is not fixed, and such case as the angular deformation value of
the arc-starting end being higher than that of the arc-blowout end exists. 相似文献
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De-jun Yan Xue-song Liu Huan-yu Xu Jian-guo Yang Hong-yuan Fang Jing-yang Lu 《Frontiers of Materials Science in China》2009,3(1):71-74
In this paper, a thermal elastic-plastic finite element method (FEM) is used to simulate the plasma welding process in order
to predict the welding distortion of automobile stator iron core. Six spatial symmetrical welding torches are adopted in the
welding process so as to make the iron core rings welded firmly and the distortion symmetric. The effect of rigid clamp on
actual welding process is replaced by the contact function between rigid body and deformation element in the MSC software,
MARC. The welding process restrained by clamp and deformation analysis after the removal of clamp was successfully simulated.
The predictions show good agreement with the test results when the rigid clamps are taken into account in the welding simulation,
which satisfies the design requirement for manufacture. 相似文献
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目的 对国际热核聚变装置中环向场线圈盒AU1段的焊接过程进行有限元数值模拟分析,探究焊接坡口类型和焊接工装对侧板焊接角变形的影响。方法 基于ABAQUS有限元计算平台,建立等截面尺寸简化的线圈盒AU1模拟件的有限元模型,通过二次开发移动单元体热源模型实现多层多道焊接模拟。在AU1模拟件的基础上设计对称和非对称的2种焊接坡口,并分析2种坡口结构侧板角变形的大小和规律。通过将防角变形工装抽象为边界条件,实现了该工装的功能,研究了防角变形工装调控焊接角变形的效果。结果 非对称坡口和对称坡口结构产生的侧板角变形规律基本相同,但前者的最终角变形为22.5 mm,大于后者的18.1 mm;在AU1结构焊接过程中,当焊接至约76 mm厚度时,角变形先是变化较快,而后逐渐趋于稳定;在焊接至约76mm厚度之前对焊接工装进行调整,可使焊接厚度为280mm时的侧板角变形由同期的22.7 mm降低至4.0 mm。结论 移动单元体热源模型很好地平衡了计算效率与准确性,使用对称坡口可以获得更小的角变形,对防角变形工装进行及时调整可以大幅度减小侧板的角变形。 相似文献
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De-An DENG 《材料科学前沿(英文版)》2010,4(2):202
Welding technology is widely used to assemble large thin plate structures such as ships, automobiles, and passenger trains because of its high productivity. However, it is impossible to avoid welding-induced distortion during the assembly process. Welding distortion not only reduces the fabrication accuracy of a weldment, but also decreases the productivity due to correction work. If welding distortion can be predicted using a practical method beforehand, the prediction will be useful for taking appropriate measures to control the dimensional accuracy to an acceptable limit. In this study, a two-step computational approach, which is a combination of a thermo-elastic-plastic finite element method (FEM) and an elastic finite element with consideration for large deformation, is developed to estimate welding distortion for large and complex welded structures. Welding distortions in several representative large complex structures, which are often used in shipbuilding, are simulated using the proposed method. By comparing the predictions and the measurements, the effectiveness of the two-step computational approach is verified. 相似文献