Cause of Fracture on Suspension Clamp of a 220 kV Transmission Line

The XGF-6X ZL102 aluminum alloy suspension clamp of a 220 kV transmission line fractured during operation. The causes of fracture on suspension clamp were analyzed by means of macro analysis, chemical composition analysis, hardness test, mechanical failure load test, radiographic inspection and fracture analysis.The results show that the size of suspension clamp did not meet the design requirements, and there were some casting defects such as pores and slag inclusions in suspension clamp, which made the mechanical failure load of suspension clamp lower than the standard requirements. During operation, the vertical load of suspension clamp increased due to icing, and finally overload fracture occurred.