基于ANSYS的输电导线线夹处动弯应变与疲劳寿命仿真分析
Simulation Analysis of Dynamic Bending Strain and Fatigue Life of Transmission Conductors at Clamp Locations Based on ANSYS
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摘要: 针对导线悬垂线夹处微风振动引发的断股问题,旨在探究其局部动弯应变特性与疲劳寿命。基于区域气象数据的Weibull分布特征提取典型风速段,建立考虑层间滑移等效抗弯刚度的LGJ-400/35导线ANSYS模型,通过分级动力学仿真提取动态响应。结合斯劳哈尔公式计算各风速段主频,运用雨流计数法与Miner线性累积理论开展疲劳评估。结果表明:线夹处微风振动主频集中在6-28 Hz,全年振动循环总次数达3.86×10?次,全年累积损伤度为0.0612。引入《架空输电线路设计规范》中的综合修正系数进行安全裕度折减后,实际疲劳寿命预测约为11.4年。研究证实了微风振动高频、低幅值的长周期累积损伤机制,并指出2-3 m/s的中低风速段(主频 13~20 Hz)联合激发的共振是导致疲劳失效的最核心因素,累计损伤占比达 82.5%,为线路目标频段防振设计提供了量化依据。Abstract: Aiming at the problem of strand breakage caused by aeolian vibration at suspension clamps of conductors, this study investigates the local dynamic bending strain characteristics and fatigue life. Typical wind speed segments are extracted based on the Weibull distribution of regional meteorological data. An ANSYS model of the LGJ-400/35 conductor is established, incorporating equivalent bending stiffness considering interlayer slip, and dynamic responses are obtained through graded dynamic simulations. The dominant frequencies for each wind speed segment are calculated using the Strouhal formula, and fatigue assessment is conducted with the rainflow counting method and Miner"s linear cumulative theory. The results show that the dominant frequencies of aeolian vibration at the clamp range from 6 to 28 Hz, with a total annual number of vibration cycles of 3.86×10? and an annual cumulative damage degree of 0.0612. After applying a safety margin reduction using the comprehensive correction coefficient specified in theSOverhead Transmission Line Design Code, the predicted actual fatigue life is approximately 11.4 years. The study confirms the long-term cumulative damage mechanism of aeolian vibration characterized by high frequency and low amplitude, and identifies that the combined resonance induced by low-to-moderate wind speeds of 2–3 m/s (dominant frequencies of 13–20 Hz) is the most critical factor leading to fatigue failure, accounting for 82.5% of the cumulative damage. This provides a quantitative basis for targeted frequency-band anti-vibration design of transmission lines.
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