Twisted-wind effect on the aerodynamic force acting on varying side-ratios tall buildings

The influence of side ratio on the aerodynamic performance of tall buildings is investigated by pressure mea-surement experiments in a mimicked twisted wind field (TWF) with the maximum twisted angle of 30 degrees and its corresponding conventional wind field (CWF). The global wind loads and distribution of local wind forces on the buildings with different side ratios are analyzed in TWF and compared with those in CWF. Additionally, the effect of side ratio on the spatial correlations of aerodynamic forces in temporal and frequency domains and their spectral features are discussed in the two fields. The results show that the aerodynamic forces are largely affected by the side ratio of tall buildings in TWF. The correlation coefficients of local lateral wind force in the TWF are decreased by 0.1-0.4 compared with those in CWF. The trajectory envelopes of the base moment components in lateral and torsional directions are positively inclined, and the building with B/D = 2 takes the maximum correlation coefficient. The spectral peak of local torsional forces is diminished with the increasing side ratio in TWF and CWF, and the peak frequency in TWF deviates from that in CWF even though the building is under the equivalent wind direction at some specific elevations. This study aims to provide some useful insights into the twisted wind effect on tall buildings with varying side ratios.