The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on...The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on the chassis regarded as a DVA.Suspension parameters of the equipment were optimized based on the modal analysis of the beam and parameter optimization of the DVA.Vertical motion equations of the carbody and equipment were derived to study the effect of the suspension parameters on the vibration of carbody,which included the suspension frequency,damping ratio,mounting position and mass.Then a 3D rigid-flexible coupled vehicle system dynamics model was built to simulate the response of carbody and equipment to track excitation.The results show that the equipment mounted on the carbody chassis can be regarded as a DVA to reduce the flexible vibration of carbody,and the optimum suspension frequency can be calculated theoretically with the first-order vertical bending mode of carbody considered.Heavy equipment should be mounted to the carbody center as close as possible to obtain a significant vibration reduction,while light equipment has quite limited contribution to that.Also,a laboratory test was conducted on the full-scale test rig which shows a good agreement with the theoretical analysis and dynamic simulations.The faster the vehicle runs,the more significant are the advantages of the elastic suspension.展开更多
To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation consi...To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation considered. And the dynamic unbalance and impact turbulence excita tion from equipment were taken into account in a single stage and twostage vibration isolation system, respectively. Results show that the excitation transferred to carbody increases with suspension stiffness but decreases with the equipment mass increasing; the vibration transmission can be reduced by increasing the equipment mass or reduce the suspension stiffness. To avoid vibration resonance, the dynamic unbalance frequency of equipment should be out of the possible range of the carbody flexible modes, and a small stiffness should be applied to reduce the impact tur bulence. A small stiffness, however, would result in a large movement of the equipment which is limited by the static deflection requirement, while a great stiffness will transfer high frequency vibration. Therefore, a preferred stiffness should make the suspension frequency of equipment a bit greater than the first bending mode of carbody. Additionally, a 3D rigidflexible coupled dynamics model was built to verify the mathematical analysis, and they show good agreements. Results show that a twostage isolation could reduce the excitation transmission and make the vibration of carbody and equipment acceptable.展开更多
基金supported by the National Science and Technology Support Program of China(2009BAG12A01-A02)the New Century Excellent Talents of Ministry of Education funded project(NCET-10-0664)+2 种基金the National Natural Science Foundation of China(Grant No.61134002)the National Basic Research Program of China("973"Program)(Grant No.2011CB711106)China Postdoctoral Science Foundation funded project(No:2014M550471)
文摘The theory of dynamic vibration absorber(DVA)was applied to restrain the vibration of carbody for high-speed electric multiple unit(EMU).The carbody was modeled as an Euler-Bernoulli beam with the equipment mounted on the chassis regarded as a DVA.Suspension parameters of the equipment were optimized based on the modal analysis of the beam and parameter optimization of the DVA.Vertical motion equations of the carbody and equipment were derived to study the effect of the suspension parameters on the vibration of carbody,which included the suspension frequency,damping ratio,mounting position and mass.Then a 3D rigid-flexible coupled vehicle system dynamics model was built to simulate the response of carbody and equipment to track excitation.The results show that the equipment mounted on the carbody chassis can be regarded as a DVA to reduce the flexible vibration of carbody,and the optimum suspension frequency can be calculated theoretically with the first-order vertical bending mode of carbody considered.Heavy equipment should be mounted to the carbody center as close as possible to obtain a significant vibration reduction,while light equipment has quite limited contribution to that.Also,a laboratory test was conducted on the full-scale test rig which shows a good agreement with the theoretical analysis and dynamic simulations.The faster the vehicle runs,the more significant are the advantages of the elastic suspension.
基金supported by the National Science and Technology Support Program of China (No. 2011 BAG10B01)the National Key Basic Research Program of China (No. 2011CB711100)+1 种基金the National Science and Technology Support Program of China (No. U1334206)the New Century Excellent Talents of Ministry of Education funded project (No. NCET-10-0664)
文摘To study the vibration transmission character istics of a flexible carbody and its suspended equipment, a vertical mathematical model of highspeed electric multiple unit was established with equipment excitation considered. And the dynamic unbalance and impact turbulence excita tion from equipment were taken into account in a single stage and twostage vibration isolation system, respectively. Results show that the excitation transferred to carbody increases with suspension stiffness but decreases with the equipment mass increasing; the vibration transmission can be reduced by increasing the equipment mass or reduce the suspension stiffness. To avoid vibration resonance, the dynamic unbalance frequency of equipment should be out of the possible range of the carbody flexible modes, and a small stiffness should be applied to reduce the impact tur bulence. A small stiffness, however, would result in a large movement of the equipment which is limited by the static deflection requirement, while a great stiffness will transfer high frequency vibration. Therefore, a preferred stiffness should make the suspension frequency of equipment a bit greater than the first bending mode of carbody. Additionally, a 3D rigidflexible coupled dynamics model was built to verify the mathematical analysis, and they show good agreements. Results show that a twostage isolation could reduce the excitation transmission and make the vibration of carbody and equipment acceptable.
