Study On Wind-Induced Dynamic Responses Of Long-Span Roof Structures

Along with the development of science and technology, the stands of stadium and grand theater are often covered with long-span flexible roof structures with beautiful shapes and new structural systems. When wind flows around roofs, the airflow will be separated to form a high suction zone, and the flexible roofs will suffer from wind-induced vibration response. So far, a limited number of research papers are related to dynamic responses of long-span flexible roofs. Long-span grid roof of grand theater is a special topic of long-span flexible roof structures, and it is important to study on wind load and wind-induced dynamic response in the field of engineering and research. Based on the combination of time-domain analysis method and frequency-domain analysis method, the dissertation designed the finite element model to study systematically on the vibration mechanism, vibration shape, dynamic response and wind-induced vibration factor of the long-span grid roof of Chongqing Grand Theater subjected to wind excitation, and some valuable results are obtained.The followings were studied:â‘ In frequency-domain, using the background modal analysis method to analysis Chongqing Grand Theater Disc2 roof, get the most contribution to the buffeting energy of the structure is calculated ,thus the RMS of the dynamic responses and displacement wind-induced vibration factor of long-span grid roofs is obtained.â‘¡In time-domain, using the time-process analysis method to analysis Chongqing Grand Theater Disc2 roof, making the simulation of the wind load by superposition of harmonic and then we can educe the curve of the time-process wind velocity of the nodes on the roof, then obtain the time history of fluctuating pressures. The RMS of the dynamic responses and wind-induced vibration factor is also obtained by direct integral method in time-domain .â‘¢After the comparison of the results of two methods, several important conclusions can be made. (1) The rules obtained from the background modal analysis method based on the quasi-steady assumption in frequency-domain are similar to those obtained by the analysis method in time-domain, and the influence of high modes can be considered. (2) Studying on the wind-induced vibration factor of Chongqing Grand Theater roof, the dissertation suggests that for engineering design, it is better to use displacement wind-induced vibration factor for computing the equivalent static wind load of long-span grid roof structures.Through analysis of Chongqing Grand Theater roof , the wind-induced vibration factor is calculated in this dissertation, can be consulted for design.