中文摘要：

正交异性钢桥面板横隔板弧形切口是疲劳敏感细节之一。为获得其轮载作用下应力响应特征,开展了随机车流下正交异性钢桥面板弧形切口应力监测。研究认为,一辆卡车通过横隔板弧形切口将产生与轴组数量对应的应力幅,其应力响应不能分辨小间距轮轴;在超载卡车作用下横隔板弧形切口将产生很大的应力响应,应力峰值可能会大于钢材的容许应力,而此时弧形切口处于双向受压状态,活载应力幅为压应力幅;研究同时发现,横隔板将受到面外弯曲作用,在轮载作用一侧的弧形切口将产生显著的面外变形。分析认为,如弧形切口出现疲劳开裂,开裂方向将在与水平面成约20°的斜上方向指向邻近纵肋。

英文摘要：

The diaphragm cutout is one of the fatigue critical details in Orthotropic steel bridge decks. This paper focuses on characteristic description of stress response of the diaphragm cutout based on field monitoring under random traffic flows. The results show that the number of stress cycles produced by the passage of one truck at the cutout merely depends on the number of axle groups rather than the axle numbers. Under overweight truck loading,the cutout may produce high level peak stress which may exceed the steel allowable stress,while the detail is undergoing biaxial compression with only compressive stress ranges. It is also found that the diaphragm indicates out-of-plane bending,and the cutout at the side close to wheel loading presents significant out-of-plane distortion. It is concluded that if fatigue cracking occurs at diaphragm cutout,it will extend in the direction with about twenty degree angle to the level and orientate upward to the adjacent rib.