Human-induced Vibration Response And Comfort Assessment Of Prefabricated Composite Floor

The appearance of composite floor improved the prefabricated assembly rate of the prefabricated building structure.It had a broad application prospect with the development of the assembly building in the future.Same as the cast-in-place floor,the composite floor was mainly excited by the pedestrian loads.For the structural details of the composite floor was different from that of the cast-in-place floor,there might be vibration comfort problems under pesestrain excitation if the composite floor was designed by the existing codes.At present,there were few reports about the vibration response and corresponding evaluation methods of comfort level of the composite floor under pedestrian loads at home and abroad In order to make up for the deficiency of the existing codes,this paper carried out systematic research on the vibration comfort issue of the composite floor under pedestrian load,and made a preliminary exploration on the evaluation method of the comfort level of the composite floor.The main contents were as follows:(1)The natural vibration frequencies,modes and vibration response of composite floor under pedestrian load were measured in the background project.The effects of the excitation frequency,load type and number of pedestrians on the vibration response of composite floor were analyzed.The results showed that vibration response of the composite floor was proportional to the excitation frequency and the number of pedestrians.Jumping load had the greatest influence on the vibration of the composite floor.(2)Combined with Monte Carlo method,the vibration response analysis method of the composite floor under random crowd excitation was proposed,which was applied in the background project.The Mean values of the peak acceleration and root mean square acceleration were 0.0586m/s~2 and 0.0169m/s~2 respectively under random crowd excitation with density of 0.75m/s~2.(3 Finite element benchmark model of the composite floor was obtained by modeling update according to the test results.The effects of number of joints,thickness of cast-in-situ slabs and thickness of prefabricated slabs on the stiffness of the composite floor were analyzed.The stiffness correction factor was obtained by fitting,which was substituted into the original formula to obtain the basic frequency formula of composite floor.Combined with the background project,vibration response of the composite floor was analyzed,and the influence of the pedestrian number,excitation mode and excitation frequency on the vibration response was studied.The vibration response of the composite floor under crowd excitation was analyzed by finite element method,and the rationality of vibration response analysis method of composite floor under random crowd excitation was verified.(4)On the basis of investigation results of this paper,evaluation criteria and research results of the comfort at home and abroad were systematically expounded.Comfort of the composite floor was evaluated by using existing standards.The results indicated that the composite floors of Xilin Middle School meet the comfort requirements of existing standards.