高电压复合绝缘子的脆断行为  

Brittle fracture of high voltage composite insulators

作　　者：戴建军[1] 梁曦东[1] 姚学锋[2] 

机构地区：[1]清华大学电机工程与应用电子技术系,北京100084 [2]清华大学工程力学系,北京100084

出　　处：《清华大学学报（自然科学版）》2005年第3期344-346,350,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家杰出青年基金资助项目(50025720);高等学校博士学科点专项科研基金资助项目(2000000315)

摘　　要：脆断是高电压复合绝缘子发生的应力腐蚀断裂现象,国内外的研究基本集中在"腐蚀"介质酸的来源上。为进一步探索脆断机理,从"应力"的角度,采用扫描电子显微镜和表面形貌测量仪研究了复合绝缘子芯棒因表面砂纸打磨痕迹等微裂纹引起的脆断,发现芯棒表面30～40μm的微裂纹在应力腐蚀环境下沿其方向向前发展。芯棒表面微裂纹尖端的应力强度因子增大,最终将导致裂纹尖端局部的损伤、萌生、演化扩展直至芯棒脆断,从而可以说明绝大多数绝缘子工作正常但极少数绝缘子发生脆断的现象。Brittle fracture is a stress corrosion cracking phenomenon which occurs in high voltage composite insulators. Previous studies all focused on the source of the 'corrosion' medium, e.g. the acid. This study focuses on the 'stress' in a brittle fracture of fiber reinforced plastic (FRP) rod along a sand paper mark with observations using a scanning electron microscope and surface measurements. The results show that 30-40 μm micro-cracks caused by the sand paper on the surface of the FRP rod lead to stress corrosion crack propagating forward along the original sand paper mark direction. These micro-cracks augment the stress intensity factor on the local FRP rod surface in a corrosive environment, with the damage leading to initiation and propagation of cracks, and finally brittle fracture. The results explain why only a few insulators suffer from brittle fracture while many others have been safely used.

关 键 词：高电压 复合绝缘子 纤维增强芯棒 应力腐蚀断裂 应力强度因子 

分 类 号：TM8[电气工程—高电压与绝缘技术] O34[理学—固体力学]