十字接头间隙对焊趾和焊根应力集中系数的影响

Influence of geometrical dimensions of joint gaps on stress concentration factor of cruciform welded joints

采用有限元法研究了主板和角接板间隙的几何尺寸对十字接头应力集中系数的影响。结果表明:非承载十字接头间隙几何尺寸与焊趾和焊根处应力集中系数成线性关系;非承载十字接头的有限元建模可以忽略间隙的影响,但接头间隙对承载十字接头焊根和焊趾处的应力集中系数有很大的影响,在有限元建模时须考虑间隙的影响;从接头间隙的几何尺寸变动的角度对承载十字接头最终疲劳失效在焊根还是焊趾给出了解释,相关文献的试验结果证实了这种看法。

The influence of geometrical dimensions of joint gaps between main plates and fillet welded gussets on stress concentration at the weld toes and at the weld roots in cruciform welded joints was analyzed by the FEM.The numerical results demonstrate that the relationship between geometrical dimensions of joint gap and stress concentration at the weld toe or at the weld root is linear.The influence of joint gap on stress concentration at the weld toe and at the weld root can be omitted for non-loaded cruciform welded joint,while the joint gap in loaded cruciform welded joint plays an important role in stress concentration.The joint gap should be considered in the process of modeling and analyzing the loaded cruciform welded joint.In the way of geometrical dimensions variation of joint gap,a explanation that fatigue failure is likely to occur either in the weld toe or at the weld root in loaded cruciform welded joint was presented,which can be proved by some published experimental results.