| The suspended giant steel frame structure system is a new type of structural system that includes a series type of structures such as giant frame structures,suspended structures,and large-span structures with excellent mechanical performance.But there is still a lack of experimental and theoretical research on this type of structure.Based on the project of the Chinese Academy of Sciences Institute of Quantum Research,the suspended giant steel frame structure system was analyzed in this paper.The structure system is filled with multi-layer sub-structure floors in a giant frame,with a middle span of 45m,which may result in low structural damping and large flexibility accompanied by a low natural vibration frequency of the floor,thereby causing a strong vibration response of the floor under the excitation of human-induced load.In this paper,through the experimental and theoretical analyses,the vibration characteristics and comfort evaluation of the suspended giant steel frame structure system were discussed.The main work is as follows:(1)Dynamic characteristic and human-induced load excitation test of the suspended giant steel frame structure system floor were carried out.The frequency distribution of the floor slab was observed through the dynamic characteristic test.The vibration tests of the floor considering various working conditions such as walking,running,jumping,etc.were performed,and the vibration response law of the floor cover under different factors such as walking route,walking frequency,number of people walking,and different floors is studied.At the same time,the influence of the infill wall panel on the vibration response of the structural system floor is analyzed and compared with experimental results.(2)Based on the SAP2000 platform,a finite element model of the suspended giant steel frame overall structure was established,and the static analysis,modal analysis,steady-state analysis and human-induced load excitation analysis were carried out through finite analysis.The deformation characteristics of the floor was detected by the static analysis;Through the modal analysis,the vibration mode and frequency of the overall structural system was observed,which aimed to make a preliminary judgment of the possibility of resonance and to clarify the research area of the structural system floor vibration characteristics.The natural vibration frequency of the floor was obtained through the steady-state analysis.Dynamic loads were applied to simulate the excitation process of pedestrian walking on the structure,and to conduct dynamic time-history response analysis;The finite element results were compared with the experimental results to verify its accuracy.(3)Floor vibration comfort evaluation methods were systematically summarized.Based on the vibration characteristics of the suspended giant steel frame structure system,the relevant comfort standards were reasonably selected,and the vibration comfort of the new structural system floor vibration comfort is evaluated.In addition,the following indexes(Frequency≥5Hz and vibration intensity≤0.02 m/s~2)were used for the vibration comfort of the suspended giant steel frame structural system.(4)Through the parametric analyses including the stiffness of hanging column,the span of sub-structure and the forced state of structural system,the vibration control factors that may affect the floor of the structure system of suspended giant steel frame were studied and discussed,which provided references for the design and application of the new structural system. |
