Numerical Simulation Method for the Rain-Wind Induced Vibration of the Three-Dimensional Flexible Stay Cable

Abstract

Under specific wind and rain conditions, the cable may exhibit low frequency and large amplitude phonomenon, which is called the rain-wind induced vibration (RWIV). Because the RWIV phenomenon encompasses interactions among gas, liquid, and solid phases, make it difficult to reproduce through numerical simulation method. In the previous research, based on lubrication theory, researchers have established theory models of two-dimensional (2D) coupled and rigid segment of three-dimensional (3D) cables for RWIV. Based on the previous research, the new numerical simulation method for RWIV of 3D flexible cable is proposed in this paper, which can reflect the interaction among the gas, liquid, and solid phases. The aerodynamics forces are calculated using comsol. The evolution of water film is calculated using matlab. In the previous studies, the cable deformation was not considered. Hence, cable vibration is derived from the solution of a single-degree-of-freedom vibration equation. In this study, the cable is treated as a deformable body. The vibration response of the cable under external force is solved using ansys. The bidirectional coupling effect between the cable and the water film is considered. The morphology of water film on the cable surface is changing with time, which causes the variation of the lift over time. Therefore, it is necessary to discretize the time so that the lift acted on the cable at each time-step can be obtained. The Restart technique in ansys is used for this purpose. Additionally, the transmission of information can be achieved by using matlab is used to control comsol and ansys. The rain-wind induced vibration phenomenon of 3D flexible cable is reproduced by using the new numerical simulation method, analyzing the variation of water film, cable lift, cable vibration under the influence of cable deformation. The mechanism of rain-wind-induced vibration is revealed again by analysing the 3D model. In addition, the advantages and necessity of the 3D cable vibration model are demonstrated by comparing it with the 2D model simulating cable vibration