Investigation Of Experiment And Numerical Simulation On Rain-wind-induced Vibration Of Strayed Cables

The strayed cable is a main bearing part of cable strayed bridge, which being lightweight, low stiffness and little damping, can be easily inspired great vibration under outsideincentive effect. The vibrations of strayed cable could creat great influence on safetyoperation and service life of the bridge.In all kinds of vibration phenomenons, the excitationconditions of wind-rain-induced vibration is the most easily to meet, and the harm is the mostserious. So the production mechanism and control measurements of wind-rain-inducedvibration of cable has be recognized as one of the most hot study issues in bridge engineeringand structural wind engineering field by researchers.This paper has been studied on wind-rain-induced vibration of cable from thecombination method of wind tunnel test, numerical simulation and theory analysis. The mainresearch contents are as follows:1. A set of3-d cable model with fixed artificial rivulet has been designed andmanufactured to measure force and pressure. An artificial solid strip lane was fixed on thesurface of strayed cable model, instead of the liquid rivulet lane attaching to strayed cablewhen wind-rain-induced vibration occurred on a real bridge. The wind pressure coefficients,aoredynamic coefficients and the relationship between the position of rivulet withaoredynamic force of strayed cable being attached by artificial rivulet have been measured byforce balance and pressure scanning valve. Compared the aoredynamic coefficients of strayedcable with3surface morphologies under differentR eand wind-angle,then providenecessary numerical reference、test basis to reveal the micro production mechanism andeffective control measurements of wind-rain-induced vibration.2. The static flow of2-d cable model and3-d cable model with fixed artificial rivulethave been taken into numerical stimulation calculation by using FLUENT software platform.Changed the flow field forms and related design parameters under study needs，the situationof air-flow was reproduced imaginally. The stream line pattern、pressure coefficients onsurface、average draft and lift coefficients on rivulet have been got to provide importantparameters for analysis of production mechanism of wind-rain-induced vibration instead of wind tunnel text.3. Differential equation of motion of strayed cabel and rivulet in the wind-rain-inducedvibration have been derived to establish the3-d still section theoretical model which beingmore tally with the actual in natural wind field. Every parameter value in the differentialequation of motion, production mechanism and the response of wind-rain-induced vibrationhas been studied. At last, such important parameters as quality,structural damping and spatialattitude of the strayed cable have be selected to analysis the influences on wind-rain-inducedvibration.4. A pressure experiment on strayed cable with the aerodynamic measurement windinghelix has been made to analyze the influence of the height and spacing of helix onaerodynamic characteristics of the strayed cable, then the distribution of wind pressurecoefficients of3-d cable model under aoredynamic messurement with different parametersand the change law of aoredynamic coefficients under different cable surface state have beenmeasured.Which provide scientific basis and reference in refinement study on aoredynamicmeasurement to control wind-rain-induced vibration.