木网壳钢板群栓节点轴向滑移刚度试验与理论研究

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.