设置U肋内隔板对钢桥面板受力性能的影响

Influence of U-rib Inner Diaphragms on Mechanical Properties of Steel Bridge Deck

为了研究设置U肋内隔板对正交异性钢桥面板受力性能的影响,以某大跨径钢箱梁桥为例,建立钢桥面板有限元节段模型,并选取4个易发生疲劳裂纹的位置,分析了车轮荷载作用下疲劳细节的应力、变形情况,确定了最不利荷载位置.结果表明:考虑设置U肋内隔板,各疲劳节点最不利荷载位置位于沿纵桥向距细节点两侧300 mm左右,U肋内隔板有效降低了顶板焊缝处应力值,增加U肋与横隔板连接刚度,提高了弧形缺口焊缝U肋焊趾的疲劳性能,但增加了横隔板焊趾开裂的可能性,建议在有内隔板情况下加强对弧形缺口焊缝横隔板焊趾处的疲劳检测与维护.

In order to study the influence of U-rib inner diaphragms on the mechanical performance of orthotropic steel bridge deck,a finite element segment model of steel bridge deck was established based on a long span steel box girder bridge,and four locations prone to fatigue cracks were selected.The stress and deformation of the four fatigue details under the wheel load were analyzed and the most unfavorable load location was determined.The research results show that considering the U-rib inner diaphragms,the most unfavorable load position is located about 300 mm from the side of the longitudinal bridge to the detail point.The U-rib inner diaphragms effectively reduce the stress at the deck weld toe.The rigidity of the U-rib and the diaphragm is increased.The fatigue property of U-rib toe of arc notch weld is improved,but the possibility of crack of diaphragm toe is increased.It is suggested to strengthen fatigue detection and maintenance of diaphragm weld toe of arc notch weld with inner diaphragms.