Jurkiewicz Bartosz, Smyrak Beata
Faculty of Nonferous Metals, AGH University of Krakow, 30-059 Krakow, Poland.
Materials (Basel). 2024 May 24;17(11):2537. doi: 10.3390/ma17112537.
Traditional ACSR overhead wires, which consist of a high-strength steel core and several layers of aluminium wires, are currently the most popular overhead line conductor (OHL) design globally. Operating conditions, particularly operating under varying stresses from Karman vortices, lead to the fatigue cracking of wires of the outer layer, followed by wires of the inner layers. Karman vortices are formed by the detachment of a laminar wind stream flowing around the conductor, which causes vibrations in the conductor called wind or aeolian oscillations. Aluminium wires are manufactured using standard batch material drawing technology. Although the fatigue strength of such wires is not standardised, there are various criteria for evaluating this characteristic, as well as established limits on the number of cycles needed to break the first wires of the outer layer. Fatigue strength also strongly depends on the geometric structure of the wire and its operating conditions. The article analyses the influence of the mechanical condition of aluminium wires used in ACSR cables on their fatigue strength. We then present results from aluminium wire fatigue tests conducted on a specially constructed test rig. In addition, fatigue cracks were interpreted using scanning microscopy.
传统的钢芯铝绞线由高强度钢芯和多层铝线组成，是目前全球最流行的架空线路导体（OHL）设计。运行条件，特别是在卡门涡街产生的变化应力下运行，会导致外层导线出现疲劳裂纹，随后内层导线也会出现裂纹。卡门涡街是由绕导体流动的层流风分离形成的，这会导致导体产生振动，称为风振或微风振动。铝线采用标准的批量材料拉伸工艺制造。虽然这种导线的疲劳强度没有标准化，但有各种评估该特性的标准，以及外层第一批导线断裂所需的循环次数的既定限值。疲劳强度还强烈取决于导线的几何结构及其运行条件。本文分析了钢芯铝绞线中使用的铝线机械状况对其疲劳强度的影响。然后，我们展示了在专门建造的试验台上进行的铝线疲劳试验结果。此外，还使用扫描显微镜对疲劳裂纹进行了解释。
