木网壳钢板群栓节点轴向滑移刚度试验与理论研究

Research on axial slip stiffness of the multi-bolted joint with slotted-in steel plate in reticulated timber shells

作为大跨木网壳常见节点之一的钢板群栓节点,在轴向力作用下极易发生滑移变形,对整体网壳的力学性能产生不可忽略的影响。为研究不同参数对钢板群栓节点轴向滑移刚度的影响,对13组,考虑螺栓直径、数量、行距、列距以及材质等级等变化参数的钢填板-螺栓节点开展了单调加载试验研究,得到不同参数节点的轴向滑移刚度及变化规律,基于单栓的半无限体地基梁理论以及群栓弹簧模型建立了节点初始滑移刚度的理论公式。分析结果表明,节点轴向滑移刚度随螺栓直径的增大以及螺栓数量的增加,总体呈现非线性的增加趋势;螺栓列距、螺栓材性对轴向刚度影响的规律性不明显。采用弹性地基梁理论分析的节点刚度与试验结果吻合度较好,可作为木网壳群栓节点轴向滑移刚度的预测分析方法。

Bolted joint with slotted-in steel plate is prone to slip deformation under the axial loading action,which has a significant impact on the mechanical properties of the whole reticulated shell.In order to study the axial slip stiffness of these joints with different structures,the monotonic loading tests were carried out on 13 groups of specimens with different bolt diameters,amounts,spacing,row spacing and material grade,and axial slip stiffness of joints with different parameters was obtained.Based on the theory of semi-infinite foundation beam with single bolt and the spring model of group bolt,the theoretical formula of the initial slip stiffness was established.The results indicated that the diameter and the number of bolts have great influences on the axial slip stiffness of the joint,and are directly proportional to the axial slip stiffness of the joint;the influencing laws of bolt spacing and bolt material properties on the axial stiffness are not obvious.The joint stiffness calculated by the elastic foundation beam theory is in good agreement with the experimental results,indicating that the theory can be used as a prediction analysis method for the axial slip stiffness of the bolted joint of the reticulated timber shell.