组合桥面板U肋螺栓接头疲劳受力性能

针对组合桥面板受力特点,采用一种宽口U肋,设计制作了1个足尺试件,通过疲劳加载试验检验U肋螺栓接头的受力性能,并通过有限元模型对接头受力进行了分析。试验结果显示,开裂源于母板栓孔边缘并最终裂透至手孔。有限元分析表明,母板的头排栓孔附近,距孔边缘约1/3孔径处应力集中明显,集中系数约为2.5;手孔形状、拼接板厚度及栓孔大小对母板栓孔应力集中影响很小;相较8 mm厚U肋的组合板或常规钢桥面板,该组合板的接头母板栓孔受力要大许多,但其疲劳强度也满足规范要求。

Fatigue Performance of Bolted Joint for U-ribs in Composite Bridge Deck

In order to study the mechanical properties of bolted joint for U-ribs in the composite bridge deck, a full-scale composite deck specimen with wide U-ribs was designed. The mechanical properties of this bolted joint were tested by fatigue loading test, and the stress of joint was analyzed by finite element model. The test results show that the crack is initiated from the vicinity of the bolt hole of based plate and propagated to the hand-hole. And the finite element analysis indicates the stress concentration located at 1/3 hole diameter from the hole edge near the head row bolt hole of the based plate is obvious, and the concentration coefficient is about 2.5; the configuration of hand-holes and the dimensions of splice plates or bolt holes have little influence on the stress concentration of the bolt hole of the based plate. Compared with the 8 mm thick U-ribbed composite plate or the conventional steel bridge deck, the stress of the bolt hole of the joint mother plate of the proposed composite plate is much larger, but its fatigue strength also meets the requirements of the code.