Dynamic response and safety characteristics of a novel horizontal fall-arrest system with steel strand track (HFAS-SS): falling experiments and simulations

This paper proposes an innovative horizontal fall-arrest system with steel strand track (HFAS-SS) for structural construction and maintenance such as power transmission towers, which is mainly used to prevent falling injuries for high-altitude workers. A total of 72 sets of fall impact tests were conducted under different fall heights, track spans, and initial preload. The mechanism of change of fall impact load, track tension and strain of HFAS-SS was studied and the dynamic response during the falling process was revealed. Then, a finite element dynamic analysis model that was verified through tests was established to further study the impact of steel strand specifications on the performance of HFAS-SS. The results show that the HFAS-SS has sufficient safety, can effectively brake and be used for high-altitude operations on the transmission line. The larger the falling height, the greater the impact load and track tension. The larger the track span, the smaller the impact load, the greater the track tension. Reducing initial preload is an effective way to reduce track tension, but this will also increase the worker’s falling height and load. When the fall factor is greater than 1, the impact load will exceed the human safety limit of 6 kN. While ensuring structural safety, the use of steel strands with small diameters ad 1 × 7 strands can better provide protection to the worker. Finally, the design process of HFAS-SS was established based on the energy balance method.