考虑螺栓连接滑移影响的输电铁塔塔身结构分析

A three-dimensional finite element model of the transmission tower body section considering the slip characteristics of node bolt connections was established in ANSYS. The axial forces of the members and the node displacements of the tower body section under vertical and horizontal loads were calculated respectively, and the effects of bolt connection node types, load types and bolt slip distances on the internal forces and deformations of the tower body section members were analyzed. Under the action of vertical loads, the slip of the bolt connections at the nodes of the diagonal members and the main members has a more obvious impact on the axial forces of the members and the node displacements of the tower body section. The changes in the axial forces of the main members of the tower body, the diagonal members of the tower legs and the inverted K diagonal members in the second panel are mostly higher than those in the horizontal load condition. Under the action of horizontal loads, the slip of the connections at the bolt nodes between the transverse bracing members and the main members is the main influencing factor, and it has a significant impact on the axial forces of the main members and the cross diagonal members near the loading point. The change amplitudes of the axial forces of the main members and the cross diagonal members in the third panel reach 34.8% and 45.2% respectively. The bolt slip distance has a relatively small impact on the maximum axial forces of the main members of the tower body and the diagonal members of the tower legs, but has an obvious impact on the vertical deformation of the loading point.

在ANSYS中建立了考虑节点螺栓连接滑移特性的输电铁塔塔身节段三维有限元模型，分别计算得到了垂直荷载和水平荷载作用下塔身节段杆件轴力和节点位移，分析了螺栓连接节点类型、荷载类型和螺栓滑移距离对塔身节段杆件内力和变形的影响。垂直荷载作用下，斜材与主材节点螺栓连接滑移对塔身节段杆件轴力及节点位移的影响更为明显，塔身主材、塔腿斜材和第2节间倒K斜材轴力变化大都高于水平荷载工况；而水平荷载作用下，横隔面杆件与主材螺栓节点的连接滑移是主要影响因素，其对加载点附近塔身主材和交叉斜材轴力的影响显著，第3节间主材和交叉斜材轴力的变化幅度分别达到34.8%和45.2%。螺栓滑移距离对塔身主材和塔腿斜材轴力最大值影响较小，但对加载点竖向变形影响明显。