基于组合热源模型焊剂片约束电弧焊T形接头温度场及应力场计算与试验研究

Temperature and Residual Stress Field of Flux Bands Constraining Arc Welding T-joint by FEA Based on Hybrid Welding Heat Source Model and Experimental Investigation

本工作通过将高斯面热源与柱型体热源耦合的方式构建了一种组合热源,并使用有限元技术对焊剂片约束电弧焊高强钢Ⅰ型三明治板T形接头焊接温度场及应力、变形场分布进行了计算,同时采用红外热成像跟踪和轮廓扫描技术获得了焊接过程温度与变形场的试验数据。通过对比计算结果与试验结果,发现二者所得焊缝形貌、焊接热循环分布与演化、焊后残余应力及残余变形分布吻合良好,从而验证了使用该组合热源模型对焊剂片约束电弧焊温度场及应力场有限元分析的有效性和可行性。同时发现,焊接过程中所产生的残余应力集中于焊缝及其附近区域,在数值上小于材料的屈服应力。并且焊接导致的变形较小,最大变形出现在面板边缘位置,说明使用焊剂片约束电弧焊对高强钢T形接头焊接时可有效控制残余变形,为大板焊接提供参考。

Acombined welding heat source model coupled by a flat gaussian and a cylindrical volume heat source was developed to analysis the evolution of welding-induced temperature,residual stress and distortion distribution during the processing of the flux band constraining arc(FBCA)welded T-joint of theⅠ-core sandwich.The experiment statistics were obtained by the infrared thermal imager and the three-coordinate instrument.By comparing the results between the experiment and simulation,it is found that the weld cross section,thermal cycle curves,welding isothermal curves and welding distortion are basically consistence between experiment and simulation,which proves the validity and feasibility of the combined welding heat source model on the analysis of this method.At the same time,it is found that the residual stress generated during the welding process is concentrated on the weld and its vicinity,which is much lower than the yield stress of the material.And the residual deformation is acceptable,that the maximum distortion happened on the edge of the panels,according to the experimental measurements.This indicates that the FBCA can effectively control the residual deformation of high-strength steel T-joints,which improves the welding technology for the sandwich panels.