基于动态应变表征220kV空心复合绝缘子机械特性的研究  

Study on Mechanical Characteristic of 220kV Composite Hollow Insulator Based on Dynamic Strain

作　　者：井谦[1] 张长征[1] 彭静[1] 刘于新[1] 刘志强 何远华[1] 

机构地区：[1]西安高压电器研究院有限责任公司,西安710077

出　　处：《电瓷避雷器》2017年第6期187-192,共6页Insulators and Surge Arresters

摘　　要：以220kV空心复合绝缘子作为试样,利用动态电阻应变仪研究空心复合绝缘子不同位置区域的最大应变和残余应变规律。试验结果表明弯曲负荷下空心复合绝缘子缠绕管受拉侧和受压侧最大应变区域都出现在离下端部附件上边缘距离45 mm处附近,这与GB/T 21429—2008(IEC 61462:1998,MOD)中应变片的粘贴位置一般推荐在离其距离30 mm稍有不同,且下端部附件对试样底部区域的影响也不尽相同,随着离下端部附件上边缘距离的增加,受拉侧受端部附件影响依次从强到弱,而受压侧依次为弱-强-弱,两侧都在距离其约45 mm处影响最小。在弯曲负荷4.5×MML(最大机械负荷)之前,不同粘贴位置区域的残余应变与最大应变百分比都小于2.5%,处在可逆的弹性阶段;空心复合绝缘子缠绕管受拉侧和受压侧的弯曲负荷与应变曲线尾部走势略有不同,具体表现在受拉侧曲线斜率逐渐增加,而受压侧曲线斜率逐渐减小,以致最后管壁两侧断裂损坏现象也不尽相同。With the use of the 220 kV composite hollow insulator, the maximum strain and residual strain exerted on the different positions of the composite hollow insulator are studied by dynamic strain in- dicator. The experimental results show that under bending moments the maximum strain of tension and compression sides of the composite hollow insulator is measured at the point about 45 mm from the lower end fitting, which is slightly different from the recommended 30 mm by GB/T 21429--2008 （IEC 61462：1998, MOD）, and that the strain exerted by the lower end fitting on the bottom area of the sam- ples is not exactly the same. With the increase of the distance to the top edge of lower end fitting, the ef- fect on tension side is from strong to weak and the effect on compression side is from weak to strong, then strong to weak. Both of them have the weakest effect measured at the point about 45 mm from the lower end fitting. Before the bending load reached 4.5 x MML （maximum mechanical load）, the percentages of residual strain divided by maximum strain of the different pasting positions are both less than 2.5%, indi- cating the elastic phase. There are different trends of the tail curve between bending load and strain on the tension and compression side of the composite hollow insulator, which is reflected in the gradually in- creased slope of tension curve and decreased slope of the compression side curve, resulting in the differ- ent fracture phenomenon on both sides of the pipes.

关 键 词：空心复合绝缘子 应力 应变 残余应变 机械特性 最大机械负荷 

分 类 号：TM216[一般工业技术—材料科学与工程]