On the analysis of cut resistance in polymer-based climbing ropes: New testing methodology and resulting modes of failure

Rock climbing ropes tend to suffer catastrophic failure when dynamically loaded over a sharp edge. Seeking to gain a better understanding of this phenomenon, a testing methodology based on a pendulum tear tester has been developed to quantify the cut resistance of polymer-based core-sheath climbing ropes in a reliable and reproducible manner. Experimental measurements indicate that the specific energy required to cut a rope is directly proportional to the linear density of the sheath component in the rope, where a high coefficient of determination between the two parameters is observed. Field tests under actual rock climbing conditions involving a granite sharp edge confirm the practical relevance of the developed laboratory methodology. An analysis of failure modes by means of scanning electron microscopy indicates that cut resistance is inversely proportional to the amount of frictional heating introduced at the point of contact between rope and sharp edge.