等边双角钢组合T形截面的轴压弯扭实用计算

Practical Calculation of Axial Compression Bending and Torsion of Equilateral Double Angle Composite T Section

为了满足在特高压输电线路中承受更大荷载的需求,并进一步减少加工焊接工作量、保证工期、节约投资,可以选择采用螺栓连接的组合角钢结构型式的输电铁塔。相比钢管构件,组合角钢加工周期短、运输和安装方便、投资费用低。本文给出T形截面组合角钢结构计算的实用公式及表格。两个等边角钢组合而成的T形截面,绕对称轴屈曲时,是中心受力、无偏心的轴心受压杆件,但由于T形截面的形心和剪心不重合,需要考虑计及扭转效应的换算长细比;钢结构规范所给的公式实用性差,根据T形截面的回转半径与角钢肢宽的近似关系,给出弯扭换算长细比的增量随着弯曲长细比的增加而递减的公式,进而得出压曲稳定的折减系数,即承载力的折减系数,制作实用表格。

In order to meet the demand of bearing more loads in transmission lines,further reduce the workload of processing and welding,ensure the construction period and save the investment,the transmission tower with combined Angle steel structure with bolt connection can be chosen.Compared with steel tube members,composite Angle steel has short processing cycle,convenient transportation and installation,and low investment cost.This paper presents a practical formula and table for calculating the combined Angle steel structure with t-shaped section.Back to back angle T section about the axis of symmetry buckling,is axial compression member,no eccentric,but because the centroid of T section and the shear center do not coincide,the need to consider the torsional-flexural buckling equivalent slenderness ratio;For the steel structure code formula of practical difference,according to the approximate relationship between T section radius of gyration and angle width,the formula is given,about the increment of slenderness ratio on the torsional-flexural buckling decreases with the increase of slenderness ratio of the flexural buckling,then the flexural buckling reduction coefficient is obtained,that is the bearing capacity reduction coefficient,making the practical table.