Dynamic Analysis of Traction Forces in a Two-Rope System: Influence of Loading Rate and Inertia

This paper examines the physical behavior of a system subjected to slow and sudden traction using an experimental device consisting of a suspended mass connected by two identical ropes. The study highlights the conditions under which either the upper or the lower rope fails, depending on the pulling regime. When the lower rope is pulled abruptly, its tension increases rapidly and exceeds the breaking limit, while the upper rope remains intact due to the inertia of the mass. In contrast, a gradual pull leads to a quasi-static state in which the upper rope supports both the applied force and the weight, causing it to break first. The analysis is extended by considering elastic properties and introducing a non-dimensional parameter related to pulling speed, allowing the identification of a critical regime. The results emphasize the combined influence of inertia, force magnitude, and loading rate on traction dynamics.