Influence of Dynamic Properties and Position of Rivulet on Rain-Wind-Induced Vibration of Stay Cables

This paper combines an experimental study and computational fluid dynamics (CFD) simulations to investigate the influence of dynamic properties and position of upper rivulet on rain-wind-induced vibration (RWIV) of stay cables. The reproduction of the RWIV of a stay cable model is first performed based on artificial rainfall wind tunnel tests with an ultrasonic transmission thickness measurement system, which can obtain the characteristics of rivulets on the surface of the stay cable model. On the basis of the test results, CFD simulations are then used to study the aerodynamic influence of an upper rivulet using two different CFD models: a vibrating cable model with a moving upper rivulet and a vibrating cable model with a fixed upper rivulet. CFD simulations suggest that the existence of the upper rivulet do not sufficiently to excite RWIV. It is confirmed that, when an upper rivulet oscillates in a specific range at the same frequency of a cable, it can significantly vary the aerodynamic force acting on the cable with the same frequency of the cable and the aerodynamic resonant excitation will lead to the occurrence of RWIV.