输电铁塔十字组合角钢构件换算长细比推导

Derivation of Equivalent Slenderness Ratio of Cruciform Angle Section Members in Transmission Towers

以输电铁塔十字组合角钢构件为研究对象,在轴心受压构件弹性弯曲屈曲理论基础上,提出了考虑剪力影响的压杆临界力的换算长细比。采用填板通过螺栓连接的十字组合角钢分别简化为刚接和铰接模型,根据分肢的变形,推导出2种计算模型绕虚轴的换算长细比。根据输电铁塔中十字组合角钢的实际布置和构造形式,推导了十字组合绕虚轴换算长细比计算公式。采用有限元方法,对十字组合角钢分肢间隙对屈曲承载力的影响进行了分析,提出了十字组合角钢绕虚轴换算长细比计算公式。

Based on elastic bending buckling theory of axial compression components, the equivalent slenderness ratio of compression components in transmission tower cruciform angle section with considering of shearwas effects is calculated. Cruciform anglebolted by filler plate is simplified as fixed and pinned connection model. According to limb deformation, the equivalent slenderness ratio of virtual axis are deduced. In accordance with actual layout and connections of cruciform angles in transmission towers, formulas of equivalent slenderness ratio related to virtual axis of cruciform angle are derived. Finite element method is used to analyze effect of cruciform angle limb clearance on buckling bearing capacity.