Dynamic Response Analysis Of Energy-consuming Supporting Frame Structures Subjected To Long-period Seismic Waves

The far-field long-period seismic wave is a seismic signal with low acceleration amplitude,relatively large velocity amplitude and displacement amplitude,and long duration.When a building structure with a long self-vibration period encounters such a seismic wave,it will generate a large earthquake response,causing serious damage to the building structure.Therefore,it is very important to study the seismic response analysis of high-rise buildings with long self-vibration period under the action of far-field long-period seismic waves.In addition,adding support to the structure can improve the overall stiffness of the structure and reduce the natural vibration period of the structure.The damage of the building structure under the action of such seismic waves will be reduced.The research content mainly includes the following aspects:(1)Selecting far-field long-period seismic waves by a certain wave selection principle and defining them.For a more comprehensive analysis of time-frequency characteristics of far-field long-period seismic waves,from its peak,peak ratio,duration,time-history curve,response spectrum,Fourier amplitude spectrum,Hilbert energy spectrum,three-dimensional time-frequency diagram,cumulative energy spectrum and other aspects are compared with ordinary seismic waves.(2)The finite element model of 3 and 20 layers steel frame structures and their supporting reinforcement structures was established by SAP2000,and the modal analysis was carried out to study the influence of support reinforcement on the natural vibration period and torsion cycle ratio of the structure.The results show that the natural vibration period of the structure is reduced after the reinforcement of the three-layer frame structure.After the reinforcement of the 20-story frame structure,the natural vibration period of the structure is greatly reduced.The support reinforcement makes the torsion cycle ratio of both structures greatly reduced.(3)Firstly,the selected 3 ordinary seismic waves and 3 far-field long-period seismic waves are uniformly amplitude-modulated according to the code,and then input into the finite element models of 3 and 20-story steel frame structures and their supporting reinforcement structures for elastic time-history analysis under earthquake action.And compared with the response spectrum analysis,the reinforcement efficiency of the structure under the action of different types of seismic waves and response spectrum analysis is studied.The seismic response of different natural vibration periodic structures under far-field long-period seismic waves is compared and analyzed.The results show that the reinforcement of the 3-layer steel frame structure is most effective under the action of far-field long-period seismic waves.The reinforcement effect under the response spectrum analysis is second,and the reinforcement effect under the action of ordinary seismic waves is the worst.The 20-story steel frame structure is reinforced,and the structure has the best reinforcement effect under the response spectrum analysis.The reinforcement effect under the long-field long-period seismic wave is the second,and the reinforcement effect is the worst under the action of ordinary seismic waves.The far-field long-period seismic wave affects the 20-story frame structure much more than the 3-layer frame structure.