支柱瓷绝缘子表面裂纹应力强度因子的有限元分析

Stress Intensity Factor Analysis of Surface Crack on Rod Porcelain Insulator through Finite Element Method

通过ANSYS实体建模方法创建了含半椭圆表面裂纹的支柱瓷绝缘子有限元模型,裂纹前缘采用三维20节点等参退化奇异单元模拟尖端的应力应变奇异性,利用1/4节点法计算了弯曲载荷作用下瓷绝缘子裂纹前沿的应力场强度因子,得出KI随裂纹尺寸、位置及载荷水平改变时的变化规律.计算结果表明:相同条件下,支柱下法兰口与底部第一伞裙之间的表面裂纹最深点具有最大的应力强度因子,且KI值随裂纹形状比的增大而减小,随裂纹深度及载荷的增大而增大.

A finite element model of rod porcelain insulator containing semi-elliptical surface crack was established in ANSYS solid modeling method.Three dimensional 20 node isoparametric degenerative singular elements were used to simulate the stress singularity of the crack tip,and the stress intensity factor （SIF） of crack front on porcelain insulator under bending was calculated in 1/4-node method.The rule of crack size,location and various load versus KⅠ was obtained.The results have shown that,under the same condition,the maximum of crack front SIFs appears at the deepest point between the lower flange port and the first umbrella skirt,and the value of K1 decreases with the increase of crack shape ratio,while increases with the increase of crack depth and load.