Vortex-Induced Vibrations Of A Low-Tension Cable-Sheave System Modeled Using Nonlinear Finite Elements

This work presents a finite element model of a cablesheave system constructed to model cable vibrations due to vortex shedding in low-tension cases. The study assesses the potential for vortex shedding to lead to detachment of the cable from the sheave. The absolute nodal coordinate formulation is utilized to define the cable structural dynamics. Vortex shedding forces are incorporated by coupling the cable’s equations of motion to a Van der Pol equation, also known as a wakeoscillator and the cable-sheave interaction is described using a contact penalty method. The study examines the contribution of vortex shedding occurring at the cable’s natural frequency to the cable motion. For the cases studied the model demonstrates that vortex shedding alone results in very small vibration amplitudes and thus is unlikely to result in cable detachment.