Study On Vibration Serviceability Of Circular Structure In Li Zijian Art Museum Under Human-induced Excitation

Over the past decade,a large number of elegant buildings with complex structure continue to emerge,such as airports,railway stations,stadiums and art galleries and other large public buildings.The vertical natural frequency of such large span flexible complicacy space structures is often low,and the structural vibration response caused by the daily activities(such as walking,running and jumping)of the users will increase significantly.Although these vibrations generally do not pose a threat to the safety of the structure,when the vibration response reaches a certain degree,it will affect the user's life,work and rest even cause panic,seriously affecting the normal use of the building.In this paper,the circular structure in Li Zijian art museum is taken as the research object,the vibration serviceability under human-induced excitation of the circular structure is studied,and the influencing factors of vibration serviceability under human-induced excitation are discussed.The circular structure in Li Zijian art museum are supported on the 3 steel core tubes with braces,which are 50m apart.The circular structure's maximum cantilever extends as long as 19m,whose maximum span is 45m.Based on the structural dynamics theory,the numerical method was used to evaluate the vibration serviceability of the structure,imposed by 23 excitations including single person walking,harmonic walking,random walking,synchronous standing up,single person jumping and harmonic jumping.The accelerations obtained from time-history dynamic analyses are compared with the limited accelerations from American Institute of Steel Construction(AISC).Results show that the structure meets the vibration serviceability.Studies find that,to the vibration serviceability design for such complex structure,designers should find out all the most unfavorable areas in the sensitive frequency range,select excitation conditions according to the building using functions and consider all the loading modes possibly occurring in the using period,especially the rhythmic excitations,such as jumping and standing up.The study on influencing factors of vibration serviceability shows that,with the increase of the structural damping ratio,the peak acceleration response decreases,especially for the the resonance frequency excitation,the method,improving the structural vibration serviceability by increasing the structural damping,is effective;to change the concrete thickness of the composite floor,although it can not effectively change the natural frequency of the circular structure,with the increase in concrete thickness,the acceleration response of the structure is significantly reduced.