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输电铁塔中螺栓连接节点的连接滑移现象十分普遍,并且其载荷-变形过程具有很大的不确定性,传统输电铁塔分析方法常常采用空间桁架模型计算结构内力,有时不能准确反映输电铁塔中构件的真实受力情况。以输电铁塔的塔身部分为研究对象,考虑螺栓连接滑移的影响建立了塔身模型的参数化有限元模型,确定了随机输入变量和输出变量,并采用拉丁超立方抽样方法,通过直接蒙特卡洛模拟,得到了弯曲和扭转载荷工况下输电铁塔结构内力,研究了螺栓连接滑移对铁塔结构内力的影响规律。通过研究发现:考虑螺栓连接滑移不确定性影响后,杆件轴力大于空间桁架模型计算结果的概率有时很大,尤其是在扭转载荷工况条件下,斜材轴力大于空间桁架模型计算结果的可能性甚至会超过75%;不同载荷工况条件下,螺栓连接滑移对杆件轴力的影响程度也不相同,在弯曲载荷工况条件下,螺栓连接滑移对主材轴力的影响相对较小,而对斜材轴力的影响相对较大,在扭转载荷工况条件下,螺栓连接滑移对载荷所在侧面的斜材轴力影响较大,而对另外两个侧面的斜材轴力影响相对较小;实际工程中可以按照不同的载荷工况以及杆件所处的位置,对采用空间桁架模型计算得到的杆件轴力进行修正,以考虑螺栓连接滑移不确定性的影响,保证构件设计阶段所用轴力的可靠性。
The connection slip phenomenon of bolted joints in transmission tower is very common, and the load-deformation process has great uncertainty. The traditional transmission tower analysis method often uses the spatial truss model to calculate the structural internal force, sometimes it can not accurately reflect the components of the transmission tower The real force situation. Taking the tower part of power transmission tower as the research object, the parametric finite element model of the tower body model was established considering the effect of bolt slip. The random input variables and output variables were determined. By using the Latin hypercube sampling method, Carlo simulation, the internal forces of transmission towers under bending and torsional loading conditions are obtained, and the influence of bolt connection slip on the internal forces of the tower structure is studied. It is found through the research that the probability of the axial force of the bar member being larger than that of the space truss model is sometimes large considering the influence of the uncertainties of the bolt-slip connection. Especially under the condition of torsional load, the axial force of the inclined member is larger than that of the space truss model The possibility of the result is even more than 75%. Under different load conditions, the influence of the bolt connection slip on the axial force of the rod is also different. Under the bending load conditions, the bolt connection slip on the main shaft axial force While the influence on the axial force of the inclined material is relatively large. Under the condition of torsional load, the bolt connection slip has a great influence on the axial force of the inclined material on the side where the load is located, while for the other two sides The influence of the axial force of the inclined material is relatively small; in actual engineering, the axial force of the rod calculated by using the space truss model can be modified according to different load conditions and the position of the rod in consideration of the uncertainty of the bolt connection slip The impact of the sex, to ensure the reliability of the axial force used in the design phase of the component.