Shaking Table Test Research on the Influence of Center-Hung Scoreboard on Natural Vibration Characteristics and Seismic Response of Suspen-Dome Structures

Abstract

The center-hung scoreboard is a large electronic display device, that usually has a significant weight and is flexibly suspended from the roof of the gymnasium. The suspen-dome structure is one of the common roof structures of gymnasiums. In order to investigate the effect of the center-hung scoreboard on the natural vibration characteristics and seismic response, including acceleration, displacement, and strain, of the suspen-dome structure and considering that the dynamic behavior of the structure under seismic action can be realistically reflected, a shaking table test was carried out based on the suspen-dome structure of the Gymnasium of the Lanzhou Olympic Sports Center. Firstly, according to the size of the shaking table, a dynamic scale model with a geometric similarity ratio of 1:20 was established. After that, the white noise excitation test and numerical modal analysis were conducted on the models with and without the center-hung scoreboard to compare the two modes’ natural vibration characteristics. Furthermore, the earthquake simulation test was carried out on the models with and without a center-hung scoreboard, and their various seismic responses, including acceleration, displacement, and strain, were compared and analyzed. Finally, the acceleration response and displacement response of the center-hung scoreboard were investigated. The results show that the higher-order natural frequencies of the suspen-dome structure will increase when the center-hung scoreboard is suspended from the roof, and the swing of the center-hung scoreboard will be excited first in the low-order mode. In addition, the various seismic responses, including acceleration, displacement, and strain, of the model with the center-hung scoreboard are all increased compared to the model without the center-hung scoreboard. Meanwhile, the influence of the center-hung scoreboard on the seismic response of the suspen-dome structure decreases from the inner ring to the outer ring of the structure. Moreover, under the action of an earthquake, the acceleration response and displacement response of the center-hung scoreboard are both extremely high. Considering the center-hung scoreboard in the analysis and design stage of the suspen-dome structure is necessary.