Wind loads and wind-induced dynamic behavior of a single-layer latticed dome

Abstract

This paper describes the results of some basic investigations on wind loads and wind-induced dynamic behavior of a rigidly jointed single-layer latticed dome with a long span. First, the wind pressures were measured simultaneously at many points on a dome model in a turbulent boundary layer which simulated the natural wind over typical urban terrain. In the wind tunnel experiments, nine models with different rise/span and wall-height/span ratios were tested. In order to investigate the structure of the pressure field on the dome, the proper orthogonal decomposition (POD) technique was applied to the pressure data. The effect of dome geometry on the structure of the pressure field is briefly discussed. Then, the dynamic response of nine latticed domes with a span of 120 m was analyzed in the time domain. The equation of motion for the structural frame of the dome was numerically integrated by using the Newmark's β method; the wind loads, expressed as the concentrated loads at the interior nodes of the network, were generated by superimposing the first eight eigenfunctions of pressure, which were obtained from the above mentioned POD analysis. The results indicate that the dynamic response is dominated by several vibration modes; that is, the first three or four axisymmetric modes and a few lower asymmetric modes with small wave numbers both in the circumferential and in the radial direction.