Vibration Response Of Pedestrian Suspension Bridge Under The Combination Of Wind Load And Crowd Load

With the increasing number of people’s tourism activities,in order to meet the needs of people to through the canyon,large-span pedestrian suspension bridges began to increase.Due to the structural characteristics of“light”and“soft”of the large-span pedestrian suspension bridge,it will produce a large vibration response under the combined effect of wind load and crowd load,causing panic and discomfort to pedestrians.At present,there is hardly any research on this part at home and abroad.Therefore,based on a large-span pedestrian suspension bridge,the article does the following work:(1)For the structural characteristic of“narrow”of the pedestrian suspension bridge deck,a solid finite element model,a finite element model of shell and girder,a triple-girder model,a single-girder model of beam4,and a single-girder model of beam18x have been established.Then based on the solid FEM model,the analysis of the mechanical model and the dynamic characteristics of the pedestrian suspension bridge deck are carried out.The results showed:For the narrow and open section bridge deck of pedestrian suspension bridges,the warping stiffness has little contribution to the torsional stiffness of the entire system,which can be neglected during calculation.(2)It will change the airflow and influence the aerodynamic parameters of the bridge deck,when people walk on the bridge.Then as the human body test model using three superposed rectangles,people are assumed to be evenly distributed on the bridge deck and the crowd density is chosen to be 0.0P/m~2,0.2P/m~2,0.5P/m~2,1.0P/m~2,and 1.5P/m~2.A wind tunnel sectional model of the bridge deck with pedestrians is designed,and the wind tunnel force test and vibration test of the sectional model were conducted.Then the changes of aerodynamic parameters of the bridge deck caused by different crowd densities were studied.(3)An ANSYS calculation program,which can calculate the vibration response of the pedestrian suspension bridge under wind load and crowd load,is prepared by using APDL parametric design language.The program has the following five functions:(1)It can calculate pedestrian-induced vibration of the pedestrian suspension bridge,when the wind load is not considered.(2)It can calculate buffeting response of the pedestrian suspension bridge,when the crowd load is not considered.(3)The effect of static wind loads on pedestrian-induced vibration is analyzed,when the wind load is considered only.(4)The effect of the changes aerodynamic parameters on buffeting response is analyzed,when the static crowd load is considered only.(5)It can calculate the vibration response of large-span pedestrian suspension bridges under wind load and crowd load.