Application of quasi-steady theory to wind load prediction

Quasi-steady theory can be used to predict wind-induced pressures (point or area-averaged) on a building given that a suitable wind speed record and mean pressure coefficients as a function of angle of attack are available. Recently, suitable records from Texas Tech University's Wind Engineering Research Field Laboratory have been collected to investigate prediction of net overall base shear on building using quasi-steady theory. Base shear prediction is investigated using: (1) quasi-steady theory where second order wind speed terms are neglected and changes in mean pressure coefficient are estimated using a linear approximation [8]; and (2) quasi-steady theory incorporating second order wind speed terms and mean pressure coefficients obtained directly from a function describing the mean pressure coefficient as a function of angle of attack of wind on the building. These two predictions are compared to those measured in the field using rms and peak values as well as power spectral density functions. Incorporation of the second order wind speed terms and a functional relationship describing mean pressure coefficients with respect to angle of attack of wind results in the better prediction of the measured net base shear.