Simulation and failure analysis of strain clamp failed caused by deterioration of contact resistance

Strain clamp (SC) is a kind of electric fittings compressed with conductor, clamp aluminum tube (CAT), steel strands and steel anchor. Good contact resistance (CR) between aluminum strands and CAT is the SC safety guarantee. Failure mechanism of SC caused by CR deterioration (CRD) was revealed by macro examination, metallograph and FEM through a failure example. Temperature and stress fields (TSFs) of SC with normal and deteriorated CR were compared in order to describe the failure characteristics of SC. Influenced by TSFs, the exposed steel strands fracture first, leading to fracture of conductor at the orifice of CAT.