毛竹内嵌杉木的螺栓连接抗拉力学性能

在竹结构中，柱脚一般会出现受拉荷载，针对该现象提出一种内嵌杉木的毛竹螺栓连接形式，设计15个内嵌杉木的毛竹螺栓连接试件并进行轴向拉伸试验。根据Karacabeyli-Ceccotti建议的50%极限荷载法确定试件的屈服荷载和屈服位移，阐述了荷载-位移曲线中不同变形阶段的特征，分析了螺栓直径和螺孔端距对连接试件的承载力和破坏模式的影响。结果表明：该连接具有一定的承载力和变形能力，连接承载力随着螺杆直径增大而增大；受拉时连接的荷载-位移曲线具有两个弹性段，且第二弹性阶段刚度下降；连接的3种破坏模式为螺杆弯坏、竹壁剪出和竹壁开裂，失效模式由螺孔端距和螺杆直径控制；基于简化力学模型推导的公式能近似地预测连接承载力。

Tensile properties of bolted connections of Moso Bamboo embedded with Chinese fir

In the actual bamboo structures, the column base is usually subjected to tensile load. In view of this, a kind of bamboo bolt connection with embedded wood was proposed. Therefore, the axial tensile test of 15 bamboo bolt connection specimens with embedded wood was designed. Firstly, the yield load and yield displacement of specimens were determined according to 50% of the maximum capacity of Karacabeyli-Ceccotti, and then the characteristics of different deformation stages in the load displacement curve were evaluated. Finally, the influence of bolt diameter and screw hole end distance on the bearing capacity and failure mode of these connection specimens was analyzed. The results showed that the connection has a certain bearing capacity and deformation capacity, and the bearing capacity increases with increase of screw diameter. The load-displacement curve of the connection has two elastic segments in tension, and the stiffness decreases in the second elastic stage. The three failure modes include screw bending, bamboo wall punching shear and bamboo wall cracking. The failure mode is controlled by screw hole end distance and screw diameter. The formula derived from the simplified mechanical model can approximately predict the bearing capacity of the joint.