郑廷银
    （南京建筑工程学院 210009）

[提要]  采用有限元法完成了折线形过渡支座、圆弧形过渡支座及直角形突变支座钢吊车梁在同一条件下的应力、变形分析；通过各受试梁的各应力场分析，找出了各支座应力分布规律的差异和疲劳裂纹敏感区；由各应力集中系数分布图，捕捉到了疲劳裂纹首发点；运用本文所建立的“疲劳裂纹扩展驱动能”等新概念，分析了各型支座的疲劳性能；最后结合制作加工的难易程度和经济分析等，提出了上述三类变截面支座的适用条件。
[关键词]  钢吊车梁 变截面支座 疲劳性能 应力集中带宽 裂纹扩展驱动能

This paper successfully obtains the stresses and strains for the abutment of steel crane beam by using the finite element method, in which the abutments are the transition of polygonal lines and right angle. Then the difference of the stress distribution rules and the sensitive regions of fatigue crack have been found by analysing the stress field in the beams tested. And the first happening point of fatigue crack is caught from the distribution chants of stress concentration factor. The fatigue property of the three kinds of abutments is studied by the new theory of "driving energy for fatigue crack expanding" proposed in this paper. At last, the applying conditions of the abutments are suggested according to the difficult degree of manufacturing and the economy analysis.
Keywords: steel crane beam; variable section abutment; fatigue property; stress concentration, driv-
ing energy; fatigue crack expanding