| In recent years,with the development of science and technology,social economy and people’s continuous pursuit of aesthetics,a large number of lightweight long-span structures have appeared,and the problem of human induced vibration has become increasingly prominent.In the problem of human induced vibration,people are not only the excitation source of vibration,but also the receptor of vibration.Ensuring the comfort of people on the structure under structural vibration is the ultimate goal of human induced vibration research.Vibration is a dynamic problem,which involves the key problem resonance.When people are moving,it can be regarded as a dynamic load with reciprocating effect.When the walking frequency is close to the structural frequency,it will cause structural resonance.It can be seen that human induced load characteristics and structural dynamic characteristics are of self-evident importance to human induced vibration.The common human induced load is walking load,and its mathematical model has been fixed,and the range of frequency has long been determined.Then the problem of ensuring the structural comfort lies in the dynamic characteristics of the structure.How to obtain the dynamic characteristics of the structure more accurately is of great significance to prevent structural resonance.The crowd on the structure does not always keep moving.For large shopping malls,exhibition halls,gymnasiums and other building structures,static crowd is a common load form on these structures,and the human body,as a vibration absorber,will certainly weaken the vibration response of the structure.The human induced vibration analysis method considering the damping effect of static crowd can obtain the actual vibration response of the structure more accurately,It is of great significance for comfort evaluation and vibration reduction design.In this context,this paper mainly carries out the following work:(1)The single plate two degree of freedom model is established to simply analyze the main influencing factors of the dynamic characteristics of the plate;A multi person simply supported plate coupling dynamic model is established to study the influence of these factors and the change of people’s spatial position on the dynamic characteristics of the plate.At the same time,the floor damping ratio is modified according to the theoretical results.(2)Based on the multi person simply supported plate coupling dynamic model,the effects of human plate mass ratio,crowd spatial position change and multi person walking on the vibration response of the plate are analyzed.(3)The dynamic characteristics of a long-span floor slab are obtained by field test,and the vibration characteristics of the floor slab under human induced load are analyzed.The influence of static crowd on floor vibration response is analyzed by setting static crowd on the floor. |
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