Study On Human-induced Vibration Of Cold-formed Thin Walled Steel And Self-leveling Mortar Composite Floor Slab

Cold-formed thin-walled steel residential system,as an important component of light steel structure,has the characteristics of environmental protection,energy saving,high space utilization,strong plasticity,convenient and fast construction,etc.As one of the main components of the cold-formed thin-walled steel residential system,the comfort of the floor has always been a hot spot of concern.Especially in terms of the vibration performance of combined floors under pedestrian loads,this study conducted research on the comfort of coldformed thin-walled steel-self-leveling mortar composite floors through experimental research and theoretical analysis.The comfort of the combined floors under pedestrian loads was the focus of the study.The main contents of this paper are as follows:(1)Based on experimental research,the mid-span deflection of the combined floors under 1k N concentrated load,natural frequency and mode shape of the combined floors under impact load,and peak acceleration and deflection of combined floors under normal walking excitation were measured,and the vibration performance of the combined floors was evaluated.The test results provided basic data for subsequent simulation analysis.(2)The numerical simulation of the experiment was conducted using ABAQUS software.The reliability of the model was verified by comparing it with the experimental data.Based on the experimental model,a large number of parameter analyses were conducted to study the effects of various factors such as walking route,walking step frequency,walking step length,number of pedestrians,pedestrian weight,damping ratio,and boundary conditions on the dynamic response of the combined floors.The analysis showed that the dynamic response of the combined floors was largest when the walking route passed through the center of the combined floors,and the dynamic response of the combined floors increased as the pedestrian load approached the center of the walking route.When the pedestrian load reached the vicinity of the center of the walking route,the response of acceleration and deflection reached the maximum.As the pedestrian load gradually moved away from the center of the walking route,the response of acceleration and deflection also decreased.The pedestrian step frequency had a significant impact on the dynamic response of the combined floors.When the fundamental frequency of the combined floors was close to an integer multiple of the pedestrian step frequency,the combined floors exhibited a large dynamic response.As the number of pedestrians and their weight increased,the dynamic response of the combined floors increased significantly,while the dynamic response of the combined floors decreased significantly with the increase of damping ratio.Changes in boundary conditions would affect the stiffness of the combined floors.With the increase of the stiffness of the combined floors,the natural frequency of the combined floors increased,and the peak acceleration and maximum deflection decreased.The results of finite element analysis can provide reference for optimizing the structure of the combined floors and improving their anti-vibration performance,which is of great significance.(3)Based on the results of parameter analysis and existing research methods,a comfort design method for the cold-formed thin-walled steel-self-leveling mortar composite floors was proposed from the aspects of frequency,acceleration,and deflection.The design method aims to reduce the vibration of the combined floors during pedestrian walking,improve their comfort and service life.In summary,this study conducted comprehensive research on the vibration performance of combined floors,and the proposed vibration design recommendations can provide reference for practical engineering,which is of great significance for the design,construction,and use of buildings.