Numerical Simulation On Wind Pressure And Equivalent Static Wind Loads Of Long Span Structures With Complex Shape

Recent years large span structure has been widely used and rapidly developedbecause of its new forms, sleek and large span. A large number of stadiums,convention centers, large train station, airport terminals etc. have been constructed.Large span spatial structure have large flexibility, low and densely distributedvibration frequency, complex modal form with different contributions to vibration,allthese features make the sensitivity of large span space structures for wind loadsgreatly enhanced.Structural design for wind loads often become the controlling factor.Oriented to the practical project of large span spatial structures, the wind pressuredistribution, wind-loading shape coefficients and equivalent-static wind loadings oflarge span structures with complex shape under undulating terrain was simulated.First, the wind-loading shape coefficients under different incoming wind directionswere computed by Fluent software, and the distribution of wind-loading shapecoefficients are quite effected by different turbulence models, span ratio, incomingwind direction and other factors.Secondly, with matlab as the tool the wind velocitytime-history was simulated based on conventional harmonic superposition method,linear filtering method of AR method and improved FFT method, which then wasturned into wind pressure time history. By comparing the efficiency and accuracy ofdifferent methods we determine the FFT method is the most suitable.By ANSYSsoftware, the mechanical model for structural system was constituted and thestructural wind-induced vibration response was calculated, which born the simulatedwind pressure time history and wind-loading shape coefficient. Then a novelequivalent static wind loading was established, where the wind-induced dynamicamplification factor was combined with the instantaneous wind pressure distributionat specific time moment. Moreover the upper and lower limits of wind effects underdifferent wind incoming directions were given as the envelope value of wind effects.The equivalent static wind load based on wind effects was obtained which can beeasily combined with other structural design load effects, facilitate the design getaccurate results. Finally, through numerical examples, the equivalent static windloadings distribution based on different equivalent targets of structural system wereobtained.