裂纹位置对焊接接头断裂参量的影响

结合焊接结构的工程安全评定,针对焊接接头熔合线上容易出现缺陷的问题,本文利用有限元计算方法,编写了断裂参量J积分计算的有限元程序,并对裂纹位置不同时的焊接接头进行了有限元计算。结果表明,无论是平面应变还是平面应力条件下,焊接接头J积分值都与全母材和全焊缝材料不同;与此同时,裂纹位于熔合线上和裂纹处于焊缝中,焊接接头的J积分值也是有所差异的,并且,这种差异在平面应变状态下表现得更加明显。在实际工作中,对焊接接头的断裂参量的计算必须考虑裂纹所处位置的影响。

On Influence of Welded Joint on Fracture Parameter with Crack in Different Location

For engineering safety assessment, considering influence of welded joint with a crack on weld, the fracture parameter of J-integral is calculated by finite element method. The result shows that, as the crack stands on melt line of welded joint, the values of J-integral are different from those of both all-base and all-weld metal. In addition, the J-integral values are different from the welded joint which contain the crack in the middle of weld seam in two conditions of both plane strain and plane stress. In the two crack locations, the change in the plane strain condition is comparatively greater than that of being in plane stress condition, especially when the welded structure, in which a crack stands on melt line of welded joint, is in plane strain. Therefore, the influence of crack location on welded structure should be considered seriously in engineering treatment.