Human-induced Vibration Analysis Of Wooden Floor And Footbridge

Compared with other building materials,timber has lighter self-weight and is easier to vibrate under the load of pedestrian,which may cause pedestrian discomfort and panic and even structural failure.Therefore,human-induced vibration should be fully considered during the design of wooden buildings and bridges.It is proved by experiment that the current Code for Design of Wood Structures in China GB 50005-2017,which takes the static evaluation index,span of the shelf,as the performance index of floor vibration,could not well reflect the actual vibration of floor.Moreover,the code,which only has provisions,is lack of details on calculation of glued laminated timber pedestrian bridge’s vibration.Aiming at the problems existing in the code,wooden floor shelves and the girder of glued laminated timber pedestrian bridges are taken as main research objects in this thesis to analyze the influence of the coupling effect between human and structure under the action of vibration.The difference between the dynamic characteristics of the new system,combined by human and structure,and that of the original structure itself is studied by numerical simulation.The formulas for calculating the dynamic response of structures subjected to single-person and crowd loads are presented.The evaluation index and control method of the degree of comfort of structural vibration are discussed.The specific contents are as follows:(1)The theoretical calculation method of structural dynamic response considering the coupling effect between human and structure is determined.The program is compiled with MATLAB.Considering the coupling effect,the calculation result is compared with that of the original structure itself,after which the influence degree and influencing factors of the coupling effect on the structural vibration response are obtained.(2)The finite element model of the interaction between human and Euler Bernoulli beam is established by ANSYS.Then,the dynamic characteristics of the new system,with the change of the position and number of pedestrian,is analyzed.(3)Acceleration is selected as the evaluation index of structural vibration comfort.For different objects of study,main girder of glued laminated timber pedestrian bridges and wooden floor shelves,the calculation formulas of maximum displacement and acceleration in the midspan under single pedestrian load are fitted by statistical analysis software SPSS,respectively.On this basis,the determination method of equivalent pedestrian coefficient under crowd load is proposed.(4)Comparing the calculation methods of structural vibration in current codes of different nations,the rationality of calculation formula of structural dynamic response is analyzed.After that,the vibration control methods of wooden floor and glued laminated timber pedestrian bridge are discussed.