WIND TUNNEL STUDY ON GALLOPING OSCILLATIONS OF SUSPENDED FIGURE-8 TELECOMMUNICATION CABLES

It has been reported that many telecommunication cables of figure-8 section suffered from operating problems and sometimes even failed because of wind-induced large amplitude oscillation, the so-called galloping of cable. In this study, three-dimensional figure-8 cable models are tested at the wind tunnel and aeroelastic behaviour of the cable was observed in detail. It is found that wind-induced significant change of the angle of attack of the cable relative to wind is the fundamental cause of galloping. The critical wind speed that triggered galloping and the initial direction of the self-excited cable motion are explained by the Den Hartog's quasi-steady treatment of the aerodynamic force with some modification.