Study On Vibration Comfort Of Floor Structure Considering Crowd Load Effect

With the improvement of building and construction technology,the adoption of new structural system and the use of light and high-strength materials,modern buildings are gradually developing towards the direction of light structure and unique shape.Because of the decrease of mass,rigidity and the increase of span,the floor system of the structure has a lower vertical natural frequency,which is easy to produce a larger vibration under the action of crowd load and produce the problem of human induced vibration comfort.However,the measured method can only analyze the floor vibration response under a few load conditions,and generally can only achieve the evaluation effect.In this paper,the numerical simulation method is used to study the analysis method and evaluation method of the floor human induced vibration comfort of a concert hall structure,and the specific content is as follows:(1)Based on MIDAS / Gen software platform,a finite element model reflecting the actual dynamic characteristics of the structure is established.According to the actual crowd load flow situation that may occur in the concert hall floor,42 load cases considering load model,step frequency,crowd number,walking path and other factors are set up.A simulation analysis method of human induced vibration comfort suitable for long-span complex structure is proposed.(2)Taking the vertical peak acceleration response and RMS root mean square acceleration response of the floor as the evaluation indexes,according to the relevant evaluation standards,the influence of step frequency,walking path,load model and number of people on the vibration response of the floor,the vibration interference degree of the floor under various working conditions and the interaction degree between different regions are analyzed.(3)12 load cases are set up.Based on the simulation analysis,the paper studies whether the RMS acceleration value can be used as the limit value of the peak factor and the integration time of the maximum transient vibration value.It is considered that the selection of the limit value of the peak factor and the integration time of the maximum transient vibration value will affect the evaluation results of the vibration comfort of the human induced floor Impact.The limit value of peak factor and the integral time of the maximum transient vibration value are given.In this paper,based on the model building,working condition setting and vibration comfort analysis and evaluation method proposed by the music hall floor structure.It can provide reference for simulation and evaluation of human induced vibration comfort of similar large-span complex structures.