覆冰单导线舞动非线性数值模拟

为研究覆冰导线的舞动响应,针对覆冰导线所受空气动力的非线性和导线大幅运动的几何非线性,采用具有3个平动自由度和1个扭转自由度的两节点索单元,建立了考虑空气动力荷载与位移和速度耦合的舞动分析有限元模型。采用对加速度中心差分、对速度向后差分的时间积分法对舞动进行非线性数值求解。利用MATLAB编制了相应的计算程序。通过对算例的舞动数值模拟验证了该方法与程序的正确性;且具有较高的计算精度及效率;并利用该方法研究了风速对舞动的影响。研究结果表明在初始攻角不变的情况下,随着风速增大,导线的振幅不断增大;但导线竖向振幅增幅较大,水平向振幅增加较小;当风速增大到一定程度,竖向振幅增加开始变得不明显,振幅最终趋于稳定值。

Nonlinear Numerical Simulation for Galloping of Single Iced Conductor

Based on the aerodynamic and geometric non-linearity of motion of iced conductor, two-node cable element with three translational and one torsion degrees of freedom at each node and considered the aerodynamic coupling with displacement and velocity was applied to establish finite element model of iced transmission line galloping. In the procedure of numerical simulation, the finite element equation was solved by time integration method and the calculation program was compiled by MATLAB, the central difference method was used to deal with acceleration and the velocity was handled by backward difference method. Numerical example was employed to demonstrate the reliable and efficient of the presented method and program. Meanwhile, the impact of the wind velocity on galloping was investigated with the program. Research results show that as the wind velocity increases, increasing the amplitude of the wire, but larger increase in the amplitude of the vertical wires, smaller increase in the horizontal amplitude; when the wind velocity increases to a certain extent, vertical amplitude increases becomes not obvious, the amplitude of the final tends to a stable value.