特高压输电塔半刚性连接K形节点受力性能研究

Study on ultimate strength of semi-rigid K-type joints in UHV transmission tower

基于螺栓受剪半刚性K形节点理论分析及有限元模型提出一种适用于此类节点的计算模型和计算方法。该方法能够较好地分析半刚性连接K形节点转动变形的组成,包括主角钢剪切变形、螺栓剪切变形、螺栓孔的变形。考虑主角钢受剪、螺栓受剪、孔壁变形对节点转动刚度的影响,从而得到节点弯矩-剪切转角(M-s)和弯矩-转角(M-)曲线。通过试验验证了该计算方法的适用性。提出的半刚性连接K形节点弯矩-转角建议计算方法量化了主角钢肢宽、肢厚、螺栓直径、节点板厚度对转动刚度的影响,但未考虑主角钢两肢边相互影响。建议计算方法也可为我国输电塔结构设计规范关于节点转动变形的具体设计提供参考。Kishi-Chen的三参数幂函数模型适用于对此类节点弯矩-转角计算,输电塔结构中此类节点的形状系数取值大致在1.5~2.2之间。

A new analytical model as well as computational method to calculate rotational deformation of K-type joints consideration semi-rigid connections in UHV transmission tower is presented based on full-scale tests of K-type joint.This method can make a good performance in calculating and analyzing the different component related to rotational deformation,including the shear deformation of the main angle-steel,the shear deformation of bolt and the deformation of bolt. It is considered that the connection rotation is mainly induced by the deformation of the main angle in shear,bolts in shear,hole wall in bearing and it provides the moment-shear rotation curve and moment-rotation curve. The three parameter power function model of Kishi-Chen is suitable for this kind of joint moment rotation calculation,resulting in shape coefficient of approximately between 1. 5 ~ 2. 2. The proposed model quantifies effects on initial rotational stiffness of limb width and thickness,bolt diameter and joint plate thickness,but cannot consider the two limbs boundary interaction of angel-steel.