大跨越架空输电导线铝部应力分布试验

Aluminum stress distribution of long-span transmission line

为了掌握大跨越架空输电导线铝部应力空间分布特性,以JLHA1/G6A-500/280型特强钢芯铝合金导线为研究对象,采用铝股丝表面激光刻槽,内嵌高灵敏、超大复用容量超弱光纤光栅,搭建了大跨越输电导线铝部应力试验平台,研究了不同张力条件下大跨越架空输电导线铝部应力分布规律,建立了大跨越导线实体有限元模型,分析了铝股应力分布特征,并验证了试验结果的正确性。结果表明:导线承受张力作用时,外层铝股和次外层铝股应力不同,外层铝股应力小于次外层铝股应力,导线同层铝股应力基本相同;铝股应力随导线张力的增大呈线性增大趋势,张力每增大1%,铝股应力增大约10%。不同导线张力作用时钢股和铝股应力均呈现环状分层特性,铝股平均应力小于钢股平均应力,铝部和钢股应力比约为3∶7;外层和次外层铝合金股丝应力沿圆周向分布不均匀,建议大跨越导线线型设计时考虑铝股丝分层特性。

To analyze the spatial distribution of aluminum stress in long-span overhead transmission line,this study focused on the JLHA1/G6A-500/280 ultra strong steel cored aluminum alloy conductor.A stress test platform for aluminum in long-span conductors was established using laser grooving on the aluminum strand and embedding ultra weak fiber gratings known for their high sensitivity and super multiplexing capacity.The research investigated the aluminum stress distribution in the long-span overhead transmission conductor under various tension conditions.A finite element model of the long-span conductor was created,and the stress distribution characteristics of the aluminum strand was analyzed,with the test results validated against the model.The results show that under tension,the stress in the outer aluminum strand differs from that in the sub outer aluminum strand,with the outer aluminum strand experiencing lower stress.The stress within the same layer of the conductor remains consistent.The aluminum strand stress increases linearly with the increase of conductor tension,with a roughly 10%increase in aluminum strand stress for every 1%increase in tension.Under different conductor tensions,both steel and aluminum strands show ring delamination characteristics.The average stress in the aluminum strand is less than that in the steel strand,with a stress ratio of approximately 3∶7 between aluminum and steel strands.Additionally,the stress distribution of the aluminum alloy strand in the outer layer and sub outer layer is uneven along the circumferential direction.This study suggests considering the delamination characteristics of the aluminum strand in the linear design of long-span conductors.