Study On The Wind-induced Vibration Of Suspender Of Continuous Steel Truss Flexible Arch Structure

As a key force-transmitting member of steel truss arch bridges,suspenders generally have the characteristics of large slenderness ratio and small damping,which results in the suspenders being particularly sensitive to wind.Harmful wind-induced vibrations may occur within the design reference wind speed,and even damage failure.Therefore,for Suspender in the actual project,it is necessary to design wind tunnel tests to check its wind resistance performance,and if necessary,take corresponding measures to suppress the wind-induced vibration of Suspender.This article takes the continuous steel truss arch structure as the engineering background,combines with the "Wind-resistent Design Specification for Highway Bridges"(JTG / T 3360-01-2018)to conduct safety assessments on the suspenders of the bridge.Based on this,the influence of common aerodynamic measures on the aerodynamic characteristics of the suspender is studied.The main work and results of this article are as follows:1.Firstly,a brief overview of the development and research methods of bridge wind engineering,which focuses on the Vortex induced vibration and galloping of slender structures such as suspenders,and finally introduces common vibration control measures for slender structures;2.Combined with "Wind-resistent Design Specification for Highway Bridges",the wind parameters required for the wind resistance inspection of suspenders are calculated,including: basic wind speed,design reference wind speed and gallop inspection wind speed.The formula method and the finite element method are used to calculate the fundamental frequency of Suspenders,respectively,the boundary condition coefficients of the formula method are fitted based on the fundamental frequency calculated by the finite element method;3.The wind tunnel static test and dynamic test of suspenders are designed.The static test mainly calculates the galloping force coefficient by measuring the static wind coefficient of suspenders,and the results show that suspenders may gallop;the dynamic test mainly analyzes the vibration of suspenders.Finally,the wind resistance of the suspender was evaluated.The wind resistance of the suspender of the bridge meets the requirements;4.Based on the box section,the effect of changing the aerodynamic measures on the aerodynamic performance of suspenders was mainly studied.A total of four aerodynamic measures were studied,including: Cutting angle of box section,Chamfering of box section,addition of deflectors and addition of winglets,etc.,and respectively compared and summarized The improvement effect of Wind resistant performance is comprehensively evaluated,which has certain reference and guiding significance for the wind resistance design of suspenders of the long-span steel truss arch bridge.