New Insight into Wire Rope Degradation and Reliability

Wire rope degradation by bend-over-sheave cycling has been analyzed by failure modes and by progress of wire breaks to replacement criteria when using both steel and nylon sheaves. The effects of sheave ratio, design factor, rope construction and the degree and consistency of remaining strength after replacement are discussed.

Critical areas of applying present rope replacement criteria suggest that impact stress at wire contacts is an important parameter to be considered. Reliability of replacement before occurrence of dangerous deterioration is discussed. Finally, measures to improve wire rope reliability are proposed.