输电铁塔单角钢结构杆件内力及稳定承载力分析

Analysis of Internal Force and Stability Bearing Capacity of Single Angle Steel Members of Transmission Tower

当前输电铁塔设计使用的杆系模型计算结果不够精确,不能准确反映杆件内力,使用更准确的计算模型并与试验结果作对比找到更合适的内力计算方法是必要的。通过对一个耐张试验塔的一个导线横担用ABAQUS实体单元模型进行试验加载模拟,将数值计算结果与试验结果进行对比,证明了数值模型计算结果的有效性。在此基础上,分析并阐述了螺栓连接的输电塔单角钢结构杆件内力的分布规律。现行真型塔试验杆件内力的测量方法不正确,不能正确反映杆件受力状态;铁塔单角钢斜材不是轴力构件,受压杆件是压弯构件,杆件弯矩包含一阶及二阶弯矩,不能忽略;双面连接的主材杆件按轴力杆计算是正确的。按《架空输电线路杆塔结构设计技术规定》及其新版《架空输电线路杆塔结构设计技术规程》,将分析对象横担的上、下平面的主要受压斜材分别用轴压构件和压弯构件的规范公式计算单角钢受压斜材的稳定应力,与实际应力进行了比较,论述了推荐方法的安全合理性。

The calculation results of the member system model used in the current design of transmission towers are not accurate enough to accurately reflect the internal forces of members.It is necessary to find a more appropriate internal force calculation method through more accurate calculation model and comparison with the test results.The validity of the numerical model was proved by comparing the numerical results with the test results by simulating the test loading of a conductor cross arm of a tension test tower with ABAQUS solid element model.On this basis,the distribution law of the internal force of the single angle steel members of the transmission tower connected by bolts is analyzed and expounded.The current measuring method of the internal force of the real tower test members is incorrect,which can not correctly reflect the stress state of the members.The single angle steel bracing member of the tower is not an axial force member,and the compression member is a compression bending member.The bending moment of the member includes the first and second order bending moments,which cannot be ignored.It is correct to calculate the main member connected on both sides according to the axial force rod.The stability stress of the main compression crossing members on the upper and lower planes of the cross arm of the analysis object is calculated by the standard formulas of axial compression members and bending members respectively according to the“Technical code for the design of tower and pole structure of overhead transmission line”and its new version“Code for design of steel supporting structures of overhead transmission line”,which is compared with the actual stress,and the safety and rationality of the recommended method are discussed.