覆冰荷载下干字型耐张转角塔的非线性稳定性分析

Nonlinear Stability Analysis of Type "T" Angle Tower under Ice Loading

为了研究覆冰荷载作用下转角塔的稳定性,以某电力设计院设计的220 kV干字型耐张转角塔为工程背景,利用数值分析软件建立铁塔的有限元分析模型。对结构进行特征屈曲分析,得到了铁塔的特征值屈曲模态,然后采用增量加载模式研究了不同覆冰厚度情况下该塔非线性稳定性,得到不同覆冰厚度下塔顶位移以及各杆件的受力情况。结果表明,覆冰和风作用下导地线的角度荷载对转角塔起控制作用,整体表现为压弯失稳破坏。给出了转角塔的失稳模式和破坏机理,研究成果可为转角塔抗冰灾设计提供有价值的参考。

In order to study the stability of angle tower under ice loading,in this paper,numerical analysis software was adopted to establish the finite element analysis model according to the original data of engineering based on a 220 KV Type ＂T＂ angle tower designed by a power design institute.First,eigenvalue buckling analysis was made on the structure in order to obtain the eigenvalue buckling mode;then the tower non-linear stability under different ice loadings was studied by analyzing the top displacement and the force of the rods in the case of changing cladded ice thickness.It can be concluded that the angle load of wires plays a main role under ice load and wind load at the same time,consequently,the whole tower performs bending damage.Instability mode and failure mechanism of angle tower have been summarized to provide the valuable reference to the design of angle towers against ice disasters.