REYNOLDS NUMBER EFFECT ON AERODYNAMIC CHARACTERISTICS OF STAY-CABLES

Cable is one of the basic construction members of a cable-stayed bridge. The wind loads on cables constitute a high proportion of total wind loads on bridge, and wind-induced vibration is an important problem of great concern in bridge design. By wind tunnel tests, force/vibration/surface pressure measurement tests were carried out, and aerodynamic forces, vibration characteristics and surface pressure distribution were studied. Results show that in a critical Reynolds number range, an un-negligible lift force appears, and the maximum of lift force coefficient is larger than the drag force coefficient in an identical Reynolds number value; that the appearance of a lift force and an unstable flow field can induce a large amplitude vibration; that from a sub-critical range to a critical range, the flow field around the cable changes to an asymmetric structure from a symmetric structure, the asymmetric flow field is the possible mechanism causing the lift force.