Flaw and Fracture Phenomena in Electrical Porcelain

The mechanical reliability of a porcelain insulator is dependent upon its ability to resist both initiation and propagation of cracks. Laboratory tests have shown that such resistance is dependent on the nature of flaws present and the magnitude and duration of load. These tests included time-load studies, crack extension testing, and a study of ultimate strength versus flaws. With a better understanding of the fracture phenomena disclosed in the tests incorporated in this paper, it may be possible to design improved insulators.