通电条件下架空导线线股应力及微风振动疲劳寿命研究

发布时间：2018-01-09 19:08

本文关键词：通电条件下架空导线线股应力及微风振动疲劳寿命研究　出处：《郑州大学》2017年硕士论文　论文类型：学位论文

【摘要】：运行状态下的架空输电导线是带电工作的,长期承受张力、微风振动和温度场的联合作用。由于张力的存在,导线的微风振动疲劳属于非对称循环交变应力下的疲劳问题,还需要考虑平均应力对疲劳寿命的影响。因为导线钢芯和铝股线胀系数的不同,各股层的应力和温度之间的关系不尽相同,所以准确分析导线在运行温度场中的应力分布对精确计算输电导线微风振动疲劳寿命很有必要。然而现有文献很少涉及导线温度对线股分层应力及微风振动特性影响的研究,针对这一问题,本文主要做了以下几方面的工作:首先基于钢芯铝绞线的结构分层特性,利用导线各股层的变形协调条件建立导线的力学平衡方程求解导线在张力和温度作用下各股层的应力,利用ANSYS建立导线的精细模型,加载后与理论计算值对比,验证理论的正确性,然后分析整体温度和径向温度对外层铝股张力的影响;然后分析了导线悬挂点处最外层铝股因导线温度的变化而引起的应力变化。其次,介绍了导线微风振动的机理,通过研究导线振动时微风输入功率、导线自阻尼功率,运用能量平衡法对输电导线振动强度进行了评估,然后分析了导线张力、地形和档距对微风振动振幅的影响,着重分析了温度、风速共同作用对导线振动的影响。最后,系统地介绍了导线寿命预测的详细过程,着重分析了导线风向、风速概率分布,通过微风振动的动弯应力和导线线股的平均应力,求解输电线的等效交变应力幅值;基于风速、风向的联合概率,得到年平均微风振动时间;通过Miner线性累计损伤原理和输电线的S-N曲线,评估输电导线的疲劳寿命。研究了输电线张力、地形、悬挂点高度,尤其是温度对输电导线疲劳寿命的影响程度。
[Abstract]:The overhead transmission lines in operation are live working and bear the combined action of tension wind vibration and temperature field for a long time due to the existence of tension. The wind vibration fatigue of conductors belongs to the fatigue problem under asymmetric cyclic alternating stress, and the influence of average stress on fatigue life should be considered, because of the difference of linear expansion coefficient between conductor steel core and aluminum strand. The relationship between stress and temperature of each layer is different. Therefore, it is necessary to accurately analyze the stress distribution of conductors in the operating temperature field in order to accurately calculate the fatigue life of transmission conductors in wind vibration. However, the existing literature rarely deals with the delamination stress of wire strands and the characteristics of wind vibration. Impact studies. To solve this problem, this paper mainly does the following work: firstly, based on the structural delamination characteristics of steel core aluminum strands. The stress of each layer under tension and temperature is solved by establishing the equilibrium equation of wire mechanics by using the deformation coordination condition of each layer of wire, and the fine model of conductor is established by using ANSYS. After loading, the validity of the theory is verified by comparing the calculated values with the theoretical values, and then the influence of the whole temperature and radial temperature on the tension of the outer aluminum strand is analyzed. Then the stress change of the outermost aluminum wire at the wire suspension point is analyzed. Secondly, the mechanism of the conductor breeze vibration is introduced, and the wind input power is studied when the conductor vibrates. The vibration intensity of transmission wire is evaluated by the energy balance method, and the influence of wire tension, topography and distance on the vibration amplitude of wind is analyzed, with emphasis on the temperature. Finally, the detailed process of traverse life prediction is systematically introduced, with emphasis on the analysis of wind direction and wind speed probability distribution. The equivalent alternating stress amplitude of the transmission line is solved by the dynamic bending stress of the breeze vibration and the average stress of the wire strands. Based on the combined probability of wind speed and wind direction, the average annual wind vibration time is obtained. The fatigue life of transmission line is evaluated by Miner linear cumulative damage principle and S-N curve of transmission line. The transmission line tension, topography and height of suspension point are studied. Especially the influence of temperature on the fatigue life of transmission lines.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM75

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