Wind-Induced Vibration Response Analysis Of Double-Arch-Support Steel Structure System

Double-arch-support steel structure system is combined with the upper tube arch andlower triangle truss arch., and with upper and lower archs jointly bearing the vertical loadsand wind loads. The cables on both sides of the upper arch are mainly used to ensure that theout-of-plane stability of the upper arch. The rigid tied bars between upper and lower archs areused to transfer loads and to strengthen the in-plane stability of upper arch. The structuresystem has an advantage of force transmission clearly and directly, and an ability to cross avery large span.Wind load will become one of the control loads, when designing the structure withfeatures of light weight, larger flexibleness and small damping. Therefore, it’s necessary toanalyze the double-arch-support steel structure system’s wind-induced vibration responsesystematically, and consider the impact of changing basic parameters on the performance ofthe wind-induced vibration response.In this paper, we firstly used mathematical tools matlab7.0to simulate fluctuating windcurve by the theory of the linear filter method and harmony superposition method. Someparameters have to be confirmed during the simulation: using the A-Information Criterion tofix the rank of AR model, determining the Cut-off frequency and time interval. And usingsome check indexes verified the accuracy of the fluctuating wind simulation programs.Contrast the fluctuating wind simulated by two simulation programs, we finally chosen thelinear filter method to simulate fluctuating wind of a double-arch-support steel stadium.Through modal analysis of the stadium that adopted the double-arch-support steel system,we obtained some conclusions of natural vibration of the structure, which showed that naturalfrequency distributed very intensive, the first three order vibration mode of the structure wereoverall vertical deformation, which represented that the structure has well overall stiffness. Bycalculated the natural frequency under different prestress, we obtained that the influence onthe natural frequency can be ignored. And the most unfavorable wind direction angle is135o bystatic analysis under the different wind angles.Wind-induced vibration response analysis was based on previous simulation offluctuating wind speed time curve of the structure. Then we calculated the wind vibration coefficient and compared with the wind vibration coefficient based on wind tunnel tests,found that the errors were not large and the maximum error did not exceed15%. Therefore,we concluded that it’s reliable to calculate wind vibration coefficients of the structure basedon simulation of the fluctuating wind. At last, we discussed wind-induced vibration responseof the structure on different references wind pressures, damping ratios and terrain roughness.The corresponding conclusions would provide a reference for similar projects.