The steel turnout is one of the key components in the medium–low-speed maglev line system.However,the vehicle under active control is prone to vehicle–turnout coupled vibration,and thus,it is necessary to identify t...The steel turnout is one of the key components in the medium–low-speed maglev line system.However,the vehicle under active control is prone to vehicle–turnout coupled vibration,and thus,it is necessary to identify the vibration characteristics of this coupled system through field tests.To this end,dynamic performance tests were conducted on a vehicle–turnout coupled system in a medium–low-speed maglev test line.Firstly,the dynamic response data of the coupled system under various operating conditions were obtained.Then,the natural vibration characteristics of the turnout were analysed using the free attenuation method and the finite element method,indicating a good agreement between the simulation results and the measured results;the acceleration response characteristics of the coupled system were analysed in detail,and the ride quality of the vehicle was assessed by Sperling index.Finally,the frequency distribution characteristics of the coupled system were discussed.All these test results could provide references for model validation and optimized design of medium–low-speed maglev transport systems.展开更多
To analyze the dynamic response and reliability of a continuous beam bridge under the action of an extra heavy vehicle, a vehicle–bridge coupled vibration model was established based on the virtual work principle and...To analyze the dynamic response and reliability of a continuous beam bridge under the action of an extra heavy vehicle, a vehicle–bridge coupled vibration model was established based on the virtual work principle and vehicle–bridge displacement compatibility equation, which can accurately simulate the dynamic characteristics of the vehicle and bridge. Results show that deck roughness has an important function in the effect of the vehicle on the bridge. When an extra heavy vehicle passes through the continuous beam bridge at a low speed of 5 km/h, the impact coefficient reaches a high value, which should not be disregarded in bridge safety assessments. Considering that no specific law exists between the impact coefficient and vehicle speed, vehicle speed should not be unduly limited and deck roughness repairing should be paid considerable attention. Deck roughness has a significant influence on the reliability index, which decreases as deck roughness increases. For the continuous beam bridge in this work, the reliability index of each control section is greater than the minimum reliability index. No reinforcement measures are required for over-sized transport.展开更多
Levitation failure occasionally occurs when a maglev vehicle runs on a track. At the moment of levitation failure, the levitation module falls and hits the track, and there is a violent impact on the maglev vehicle-br...Levitation failure occasionally occurs when a maglev vehicle runs on a track. At the moment of levitation failure, the levitation module falls and hits the track, and there is a violent impact on the maglev vehicle-bridge coupled system. In this paper, the response of the maglev vehicle-bridge coupled system at the moment of and after levitation failure is analyzed, and three methods of reducing the vibration are proposed. First, a dynamics model of the maglev vehicle-bridge coupled system, which considers the control system, five flexible bridges, and track irregularity, is established, and the correctness of the model is verified using test data. The system response for different failure cases is then analyzed. Finally, the three methods of reducing vibration under levitation failure are proposed, and their effectiveness is evaluated. The results show that the failure position and speed barely affect the response, whereas the maximum impact forces due to levitation failure reduced by 13%, 63%, and 50% by adopting the three methods, namely connecting the first and third coils in series, coupling the ends of the levitation module vertically, and adopting two sets of anti-roll devices, respectively. When the latter two schemes are combined, the maximum impact force reduced from 133 kN(without vibration-reduction measures) to 9 kN, and the vibration-reduction measure is also effective for failures of the levitation units at the ends of the vehicle.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant No.51875483)the Independently Funded Research Project of State Key Laboratory of Traction Power(Grant Nos.2020TPL-T01 and 2020TPL-T04).
文摘The steel turnout is one of the key components in the medium–low-speed maglev line system.However,the vehicle under active control is prone to vehicle–turnout coupled vibration,and thus,it is necessary to identify the vibration characteristics of this coupled system through field tests.To this end,dynamic performance tests were conducted on a vehicle–turnout coupled system in a medium–low-speed maglev test line.Firstly,the dynamic response data of the coupled system under various operating conditions were obtained.Then,the natural vibration characteristics of the turnout were analysed using the free attenuation method and the finite element method,indicating a good agreement between the simulation results and the measured results;the acceleration response characteristics of the coupled system were analysed in detail,and the ride quality of the vehicle was assessed by Sperling index.Finally,the frequency distribution characteristics of the coupled system were discussed.All these test results could provide references for model validation and optimized design of medium–low-speed maglev transport systems.
基金Project(50779032)supported by the National Natural Science Foundation of ChinaProject(20090451330)supported by the Postdoctoral Foundation of ChinaProject(BS2013SF007)supported by Shandong Scientific Research Award Foundation for Outstanding Young Scientists,China
文摘To analyze the dynamic response and reliability of a continuous beam bridge under the action of an extra heavy vehicle, a vehicle–bridge coupled vibration model was established based on the virtual work principle and vehicle–bridge displacement compatibility equation, which can accurately simulate the dynamic characteristics of the vehicle and bridge. Results show that deck roughness has an important function in the effect of the vehicle on the bridge. When an extra heavy vehicle passes through the continuous beam bridge at a low speed of 5 km/h, the impact coefficient reaches a high value, which should not be disregarded in bridge safety assessments. Considering that no specific law exists between the impact coefficient and vehicle speed, vehicle speed should not be unduly limited and deck roughness repairing should be paid considerable attention. Deck roughness has a significant influence on the reliability index, which decreases as deck roughness increases. For the continuous beam bridge in this work, the reliability index of each control section is greater than the minimum reliability index. No reinforcement measures are required for over-sized transport.
基金supported by the National Natural Science Foundation of China (Grant No.52102442)the Fundamental Research Funds for the Central Universities (Grant Nos.2682022CX060 and 2682023GF002)。
文摘Levitation failure occasionally occurs when a maglev vehicle runs on a track. At the moment of levitation failure, the levitation module falls and hits the track, and there is a violent impact on the maglev vehicle-bridge coupled system. In this paper, the response of the maglev vehicle-bridge coupled system at the moment of and after levitation failure is analyzed, and three methods of reducing the vibration are proposed. First, a dynamics model of the maglev vehicle-bridge coupled system, which considers the control system, five flexible bridges, and track irregularity, is established, and the correctness of the model is verified using test data. The system response for different failure cases is then analyzed. Finally, the three methods of reducing vibration under levitation failure are proposed, and their effectiveness is evaluated. The results show that the failure position and speed barely affect the response, whereas the maximum impact forces due to levitation failure reduced by 13%, 63%, and 50% by adopting the three methods, namely connecting the first and third coils in series, coupling the ends of the levitation module vertically, and adopting two sets of anti-roll devices, respectively. When the latter two schemes are combined, the maximum impact force reduced from 133 kN(without vibration-reduction measures) to 9 kN, and the vibration-reduction measure is also effective for failures of the levitation units at the ends of the vehicle.
