Wind-Resistance Performance Study On Double Chain Flexible Steel Rope Suspension Bridge

Suspension bridge is a kind of flexible structure which spanning capacity is strong,it's very sensitive under the wind load, so, analysis of wind resistance is a very important link in the design, construction and operation stages of bridge, ensuring the bridge structure under wind load has reliable stability and security.At present, the analysis method of wind resistance on suspension bridges has theoretical analysis and wind tunnel test and numerical simulation method mainly,among them, the numerical simulation method is widely used due to it's the advantages of high efficiency, economy, accurate of calculation results.This paper takes the bridge of tells of the Yellow River downstream of the reservoir as the engineering background. The main span of the bridge is 180 m, bridge deck width is 4.5m and main cable rise-span ratio is 1/12, the wind- induced response is very obviously under the wind load, it's necessary to analysis the wind resistance of the bridge. the analysis of bridge wind resistance is based on the computational fluid dynamics and establish differential control equations, then use the method of numerical to calculation, so as to achieve the purpose of analyzing the wind resistance of bridge structure. The content of analyzing includes: determining the bridge design wind speed and its characteristic parameters; analyzing Wind-induced static response of the structure of the bridge by solving the coefficient of three component force; analyzing wind- induced dynamic response of bridge structure by solving the chattering forces.In order to compare the wind- induced response of double chain suspension bridges and single chain suspension bridge under different wind angle of attack, Single chain suspension bridge finite element model was established on the basis of ensuring the double chain suspension bridge main cable cross section area and the rise-span ratio unchanged same, and then set out to do wind- induced static simulation analysis and dynamic buffeting time-domain simulation analysis for double chain suspension bridge and single chain suspension bridge respectively.(1) Static analysis include: having simulated the static coefficient of three component on the basis of computational fluid dynamics theory in the wind angle of attack from-6~6 degrees, meanwhile calculate the static three component force, and the loading the double chain suspension bridge and single chain suspension bridge, comparing and analyzing the result of the calculate finally.(2) The dynamic analysis of bridge is researching the bridge structure response under the buffeting force of fluctuating wind. simulated fluctuating wind through MATLAB, obtained buffeting force time history by generation it into the buffeting force model under different wind angle of attack, loading the double chain suspension bridge and single chain suspension bridge, and the set out to do transient dynamic analysis, meanwhile, comparing and analyzing the result of the calculate, So as to provide reference for selection of the structure of the bridge.