INFLUENCES OF TRAIN SPEED AND AXLE LOADS ON LIFE CYCLE OF RAIL FASTENING CLIPS

Railway fastening clips play an important role in the stability and safety of railway track systems. There are various studies conducted on fastening clip failure mechanism. Although the majority of these studies indicate that fatigue is the main cause of clip failure, little attentions has been paid to parameters influencing clip fatigue characteristics. In response to this need, a new testing machine was developed by which the structural and loading conditions of fastening clips are simulated in a laboratory. Clip permanent deformations were measured for various track operational conditions, and consequently correlations were developed between clip plastic defamations and track axle loads as well as train speeds. The results obtained pave the way of determining the required clip maintenance cycles for various track loading conditions.