熔合线含裂纹焊接接头复合角的研究

Study on Mixity Angle of the Welded Joint with Cracks Located at the Fusion Line

结合裂纹尖端应力应变场的分布规律,讨论了熔合线上含裂纹焊接接头的COD断裂参量的分解情况。应用有限元方法分析了不同载荷作用下,不同组配焊接接头复合角与焊缝宽度的关系。进一步对熔合线上含裂纹焊接接头的复合角与焊缝应变硬化指数的关系进行了研究。结果表明,焊缝宽度、焊缝应变硬化指数以及接头组配对焊接接头复合角有很大影响。相对于焊缝宽度而言,强度组配对复合角有更为明显的影响,并且高组配和低组配焊接接头的复合角随着外加载荷的增加有相反的变化趋势。在同一外加载荷下,接头复合角随着焊缝应变硬化指数的增加而减小。

Considering the stress-strain field distribution rules of welded joints containing single-edge crack on fusion line, the fracture parameter COD is decomposed into two parts of mode Ⅰ and Mode Ⅱ. By using the finite element method, the relationship between mixity angle and width of welded seam of welded joints containing single-edge crack on the fusion line was studied under the different load levers. Moveover, the relationship between mixity angle and the strain hardening exponent of welded seam was also studied. The results show that the effect of the width and strain hardening exponent of welded seam and strength matching on mixity angle is evident. And the effect of strength matching on mixity angle is more significant than that of width. In addition, the change tendency of mixity angles of Overmatched and undermatched welded joint is reversed. The value of mixity angles becomes smaller with increasing strain hardening exponent at the same load level.