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大跨越输电线路在较低的风速下可能产生高频、低振幅的横风向微风振动。应用空间曲梁插值函数与应变位移关系,建立结点6自由度的输电线分析模型。采用Scanlan提出的经验非线性模型表达涡激力,将单自由度体系输电线自阻尼功率等效为模态自阻尼系数,引入条带假设形成了基于更新的Lagrange格式的涡激振动运动方程,对方程进行了振型分解求解。算例分析表明,采用未考虑抗弯刚度的曲梁索单元模拟输电线的微风振动与三节点索单元吻合较好,但忽略抗弯刚度会低估高频的微风振动振幅。
Large-span transmission lines may generate high-frequency, low-amplitude transverse wind breeze vibration at lower wind speeds. Based on the relationship between interpolation function and strain displacement of space curved beam, a 6 - DOF power line analysis model was established. The experiential nonlinear model proposed by Scanlan is used to express the vortex-induced force. The self-damping power of a single-degree-of-freedom system is equivalent to the modal self-damping coefficient. The vortex-induced vibration equations based on the updated Lagrange scheme are formed by introducing the strip hypothesis. The equation is modeled and solved. The case study shows that the breeze vibration of the simulated cable with curved beam elements without considering the flexural rigidity is in good agreement with the three-node cable element. However, neglecting the flexural rigidity will underestimate the breeze vibration amplitude at high frequencies.