Wind-induced vibration response analysis of high-rise lattice structure by considering modification effect for three-dimensional spatial and nonlinear vibration mode shape

Based on the high frequency force balance (HFFB) wind tunnel test results of an idealized high-rise lattice TV tower, the measured base moments were first modified by considering the inherent semi-rigid HFFB scaled model in the wind tunnel test. The modification effect of coupled three-dimension and nonlinear modal shapes and aerodynamic wind loading coupling to the wind-induced response of the high-rise TV tower was investigated by the proposed six different alternative methods respectively. Under the load cases of five wind azimuths, the wind-induced displacements in along-wind and across-wind direction by considering the modal shape and aerodynamic wind loading coupling modification effect were then compared with those corresponding results evaluated by the assumption of idealized one-dimension straight line modal shape in each direction along the major axes of the investigated high-rise structure. The comparison results showed that almost same conclusions can be obtained for the wind-induced responses in the five wind azimuths loading conditions. Compared with wind-induced displacement from the ordinary methods with one-dimension straight line modal shape assumption, the RMS values of wind-induced displacements atop of the structure could be reduced by about 21%~37% when the modification effect of coupled three-dimension and nonlinear modal shapes was considered.