Theoretical And Experimental Study On Vibration Reduction Of Pedestrian By Damping Cable

With the economic development,more and more people move to cities,the urban traffic flow increases,and the road pavement is widened.At the same time,due to the progress of high-strength material technology,the structural span of pedestrian bridges designed in various cities is becoming larger and larger.The increase of bridge span means that the fundamental frequency of the structure decreases.When the fundamental frequency of the structure falls within the range of pedestrian walking frequency,human induced vibration is likely to occur.Taking the typical simply supported steel box girder pedestrian bridge as the research object,this paper carries out theoretical and Experimental Research on the damping cable damping method of pedestrian bridge,and completes the following work:1.A self anchored damping cable method which can be applied to pedestrian overpass is proposed,and the vibration differential equation of pedestrian bridge damping cable structure is established through force analysis.The analytical formula of additional damping ratio brought by damping cable to the structure is obtained by solving the differential equation.Then,the channel steel is used to simulate the simply supported beam,and the correctness of the analytical solution of damping ratio and the damping effect of self anchored damping cable are verified by indoor model test.2.The influence of damping parameters on the damping performance of cable is analyzed.Then,the forced vibration response of the additional structure of the damping cable is solved,and the influence of the viscosity coefficient of the damping cable is analyzed according to the amplitude frequency response curve,the analytical formula of the optimal damping is obtained,and the theoretical system of the damping cable is improved.3.The application of finite element method of pedestrian bridge damping cable is discussed,and the finite element dynamic equation of experimental beam damping cable system is established,which is analyzed and solved by MATLAB software.The analysis results show that the pedestrian bridge is prone to large vibration under pedestrian resonance excitation,and the installation of damping cable can effectively suppress the vibration of the structure.4.The dynamic analysis of a circular pedestrian overpass in Changde is carried out through ANSYS finite element software.The analysis results show that the bridge may have large vibration under crowd load,which does not meet the requirements of vibration comfort.According to the structural characteristics of the circular overpass,a damping cable damping scheme is designed in this paper.After installing the damping cable,the maximum acceleration response of the structure can be reduced by 91%.