Impact failure mechanism of kernmantle ropes for fall protection from heights

Ropes, as lightweight and supple safety equipment, are being increasingly utilized in applications such as rock climbing and high-altitude work. However, the response behavior of ropes under the impact of falls and the mechanisms of fatigue failure are not yet well understood. This study constructed a synchronized impact force-displacement testing apparatus to investigate the impact behavior of a nylon core-sheath rope during falls, and compared the macroscopic and microscopic differences of the ropes before and after failure. It also explained the mechanisms of rope impact failure from multiple perspectives. The research found that the shearing action between the strands of the rope is the primary cause of failure, and that thermal damage and mechanical friction are also significant factors in impact failure. This has guiding significance for the proper use of safety ropes and the development of ropes with enhanced impact resistance.