An Adaptable Swivel Button Clamp with Enhanced Fatigue Durability

This paper documents the design analysis and experimental validation undertaken to enable replacement of a galvanized, malleable cast iron swivel clamp button, used within the overhead line system, with a machined from billet, stainless-steel alternative. The German FKM design code is used to assess the durability of both components whilst the experimental work is used to demonstrate the static strength of the stainless-steel button. The analysis demonstrates that the cast iron button may not have the required 6 million cycle durability. Investigation of a failed cast-iron button has indicated that poor casting quality, lack of adherence to design specifications and poor galvanizing may all have contributed to failure. The stainless-steel alternative is predicted to exceed the required life span and provides greater system design flexibility.