IEEE task force report: Brittle fracture in nonceramic insulators

A description of the composite insulator brittle fracture phenomenon suitable to allow correct diagnosis of a failure is provided. This paper reports on the number of brittle fractures that have occurred around the world and contains specific empirical data surrounding composite insulator brittle fractures in the U.S. It also includes several case studies of in-service failures to inform the reader of the diversity of initiating causes. The current state-of-knowledge on the brittle fracture mechanism is presented. Based on what was learned during the study, possible actions that can be taken by manufacturers and users to reduce frequency of occurrence are suggested.