输电塔螺栓搭接节点滞回性能试验研究

Experimental study on the hysteretic performance of bolted lap joints of a transmission tower

在输电塔受力振动期间,节点往往承受往复荷载的作用。为研究输电塔典型螺栓节点在往复荷载作用下的力学性能,设计了21组典型螺栓节点试件。通过进行3组单调加载试验及18组低周往复荷载试验,得到了节点试件的荷载-位移曲线,研究了荷载类型及节点参数对螺栓节点力学性能的影响,并分析了节点在往复荷载下的力学行为。结果表明:荷载的类型对节点的破坏模式以及滑移荷载影响不大,主要影响了节点的极限荷载以及其相对应的位移;螺栓在螺孔中位置的不确定性以及多螺栓行为不一致性导致了试验与模拟结果之间的差异;螺栓节点的强度随着螺栓规格和等级的增加而增大,但孔距对其影响较小;节点的极限承载力随着螺栓数量的增加而增大,但并不都是呈线性增加。所得结果为输电塔力学分析提供参考。

During the vibration of a transmission tower,the joints often bear cyclic loading.To study the mechanical properties of typical bolted joints of transmission towers under reciprocating load,twenty-one groups of typical bolted joint specimens were designed.Through 3 groups of monotonic loading tests and 18 groups of low cyclic loading tests,the load-displacement curves of the joint specimens were obtained.The effects of load types and joint parameters on the mechanical properties of bolted joints were studied,and the mechanical behavior of the joints under cyclic loading was analyzed.The results show that the load type has little effect on the failure mode and slip load of the joint,mainly affecting the ultimate load of the joint and its corresponding displacement.The difference between test and simulation results is caused by the uncertainty of bolt position in the bolt hole and the inconsistency of multi-bolt behaviors.The strength of bolted joints increases with the increase of the bolt diameter and grade,but the hole spacing has little effect on it.The ultimate bearing capacity of joints increases with the increase of the number of bolts,but not all of them increase linearly.The results provide a reference for the mechanical analysis of transmission towers.