Finite Element Model Updating、CED Numerical Simulation And Wind Resistant Optimization Of Large Span Roof Structures

With the development of structural analysis theories and construction technology,more and more modern large span roof structures emerge in urban cities. Due to theirfeatures of high flexibility, light weight and low damping, large span roof structuresare usually controlled by wind load during the design process. Field measurement,wind tunnel test and numerical simulation are major approaches for wind engineeringresearch.Taking several modern large span roof structures as examples, such threeapproches are adopted to study their finite element model updating, numericalsimulation and wind resistant optimization.The main contents of this dissertation arelisted as follows:1. Based on the modal data form full-scale measurements, the complex method isemployed in the finite element model updating for the roof structure of GuangzhouInternational Sports Arena. The result of complex method is then compared with thatof first-order algorithm in ANSYS, improved BP neural network algorithm and PSOalgorithm. The study shows that the modal frequencies after the updating work canwell match with the modal data from full-scale measurement, the updated model willprovide a fiducial model for the next wind resistant optimization, and the complexmethod is better than other three mehods.2. Through the Reynolds averaged N-S equations and SST turbulence model,wind-induced pressures on a portal framed structure are predicted byCFD(Computational Fluid Mechanics) numerical simulation technique.The simulationresults are compared with those of wind tunnel tests. Distribution characteristics ofwind pressures on the roof are discussed and concluded on the basis of numericalresults, which will provide guidance for the wind-resistance design of similiarstructures.3. After taking wind loads obtained from wind tunnel tests as the mainenvironmental loads, the sectional dimensions of structural members as the designvariables, structural strength as constraint condition, and the total volume of structuremembers as the objective function, the mathematical model of wind-resistantoptimization for a large span roof structure is established. Optimization analysis the Earea roof structure of Guangzhou International Convention&Exhibition Centre isconducted based on equivalent wind load, time-domain method and complex methodand comparative analysis of structural dynamic characteristics before and after theoptimization is made.The results show that wind-resistant optimization will reduce steel comsuption of the whole structure, make structural members work togetherrationally and coordiantely, and decrease structural deflection.