Analysis of cableway non-linear oscillations induced by wind forces

In the paper, traditional hypotheses of cableways engineering regarding wind action are checked using a numerical procedure which considers a 3-D wind field, its variability in space and time and the aerodynamic forces due to exposure of both the track rope and the passengers- vehicle to the wind flow. The aim is to capture the buffeting response and aeroelastic phenomena, such as galloping, due to ice accretion. The track rope is modelled by cable finite elements directly formulated in the global frame of reference. Aerodynamic forces on cables are computed from sectional forces according to the quasi-static theory. The passengers-cabin is considered stationary along the track rope and is modelled as a rigid body formulated adopting a finite-rotation kinematics; the aerodynamic forces due to the wind acting on the cabin surfaces are also considered. The static configuration of the system is computed adopting the dynamic relaxation technique while standard step-by- step procedure, with Newton-Raphson type iterations for equilibrium correction, is used for integrating the equations of motion.