Excessive vibrations inside buildings in the Lihu New Village caused by the Shenzhen Metro Line 2 underground railway were investigated by conducting analyses of the tunnel,the track irregularities,the stiffness of th...Excessive vibrations inside buildings in the Lihu New Village caused by the Shenzhen Metro Line 2 underground railway were investigated by conducting analyses of the tunnel,the track irregularities,the stiffness of the fastening system,and the vibrations of the track system and the building at different speeds.A numerical simulation based on the dynamic coupling theory of the vehicle-track system was used to verify the experimental results.Suitable countermeasures were investigated.The results show that rail corrugation is the primary reason for the excessive vibration,and an increase in the stiffness of the vertical fastening system is the secondary reason.The solution was to eliminate the rail corrugation using rail grinding and decrease the vertical stiffness by changing the fastening system.The results of this study provide references for solving vibration problems caused by rail lines.展开更多
Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion ...Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion for unstable motion and occurrence mechanism was studied. A comparison was performed between the oscillation responses of the stay cable obtained from calculated model and previous results. The results indicate that the analysis model can reflect the main characteristics of wind-rain-induced vibrationt of the cable which is amplitude- and velocity-restricted, and it is probably related with the periodic vortex shedding of wake flow. It is essential for the occurrence of rain-wind-induced or wind-induced vibration of cable that the derivative of lift coefficient with respect to transient angle of attack is less than zero. When rain-wind-induced vibration occurs, the aerodynamic force has a dual function for the vibration, and the maximum amplitude of stayed-cable is determined by the relative value of aerodynamic exciting force and aerodynamic damping force.展开更多
基金Projects(U1734207,51978585)supported by the National Natural Science Foundation of ChinaProject(2016 YFE 0205200)supported by the National Key Research and Development Program of China。
文摘Excessive vibrations inside buildings in the Lihu New Village caused by the Shenzhen Metro Line 2 underground railway were investigated by conducting analyses of the tunnel,the track irregularities,the stiffness of the fastening system,and the vibrations of the track system and the building at different speeds.A numerical simulation based on the dynamic coupling theory of the vehicle-track system was used to verify the experimental results.Suitable countermeasures were investigated.The results show that rail corrugation is the primary reason for the excessive vibration,and an increase in the stiffness of the vertical fastening system is the secondary reason.The solution was to eliminate the rail corrugation using rail grinding and decrease the vertical stiffness by changing the fastening system.The results of this study provide references for solving vibration problems caused by rail lines.
基金Project(51078170) supported by the National Natural Science Foundation of ChinaProject(10JDG097) supported by Jiangsu University Talents Funds,China
文摘Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion for unstable motion and occurrence mechanism was studied. A comparison was performed between the oscillation responses of the stay cable obtained from calculated model and previous results. The results indicate that the analysis model can reflect the main characteristics of wind-rain-induced vibrationt of the cable which is amplitude- and velocity-restricted, and it is probably related with the periodic vortex shedding of wake flow. It is essential for the occurrence of rain-wind-induced or wind-induced vibration of cable that the derivative of lift coefficient with respect to transient angle of attack is less than zero. When rain-wind-induced vibration occurs, the aerodynamic force has a dual function for the vibration, and the maximum amplitude of stayed-cable is determined by the relative value of aerodynamic exciting force and aerodynamic damping force.
