Study on the Comfort of Pedestrians on Landscape Footpath Paved on the Suspension Monorail System

This is the first time that the landscape footpath is realized on the suspension monorail system. To study the comfort of pedestrians on the landscape footpath when the vehicle passes, the dynamic responses of the track beam and the landscape footpath at different speeds were analyzed using the established vehicle-bridge dynamic analysis model. To evaluate the comfort of pedestrians on the landscape footpath, two indexes, Root Mean Square (RMS) value of acceleration (ISO 10137) and peak value of acceleration (EN 03), were adopted. Results show that the displacement and acceleration responses of landscape footpath and track beam are obviously different. Vertical displacement of the track beam is much larger than that of the landscape footpath due to the eccentric load of vehicles. Due to the displacement and rotation of the structural components which support the landscape footpath, the lateral response transferred to the landscape footpath would be slightly weakened. Maximum RMS values of the lateral and vertical acceleration of landscape footpath are 0.162 m/s2 and 0.169 m/s2, respectively, which meet the requirements of ISO 10137. Peak lateral acceleration is 0.546 m/s2, which reaches CL3 standard, and the peak vertical acceleration is 0.548 m/s2, which reaches CL2 standard. Lateral comfort is slightly worse than vertical comfort.

Analysis of Long-Term Durability Monitoring Data of High-Piled Wharf with Anode-Ladder Sensors Embedded in Concrete

The structural durability monitoring (SDM) system for a high-piled wharf in the Tianjin Port of China is devised and deployed with an anode ladder sensor, which provides a means to monitor the state of steel corrosion for the wharf. In this project, the anode-ladder sensors are installed on the reinforced concrete components of the front platforms. After the installation, the monitoring data from the anode-ladder sensor was collected for 40 months. Based on the monitoring data for 40 months, it is proven that the resistance of concrete will be significantly affected by the change in temperature, and the increase in temperature will cause the drop in concrete resistance. Furthermore, the data of the anode-ladder sensor set in the track beam of the front platform shows that the current in anode A1 and A2 relative to the cathode exceeded 15 μA during the four-month period, which is abnormal. The main reason is the influence of concrete temperature and humidity. Therefore, the monitoring data for current, voltage, resistance, and temperature should be combined to determine the activation state of the anode, and cannot be determined simply using the current value.

Study on Coupled Vertical Vehicle-Bridge Dynamic Performance of Medium and Low-Speed Maglev Train

The levitation stability of maglev trains is determined by the interaction of vehicle-bridge dynamic characteristics. The state change of vehicle and track beam will affect the dynamic performance of maglev trains. In order to study the levitation characteristics of maglev trains, a coupled vehicle-bridge dynamic model based on an elastic beam was established to study the influence of beam stiffness and vehicle load on the dynamic performance of the maglev system. In the form of numerical simulation, the time-domain characteristics of key characteristic variables, such as levitation gap and vertical deflection of track beam, under different working conditions of stiffness and load were analyzed. The simulation shows that the levitation system can smoothly converge to the stable value under each working condition, which indicates the rationality of the field test. Based on the Shanghai Lingang medium-and-low-speed maglev test line, the maglev test was carried out, and the time-domain and frequency-domain characteristics of the above key variables were analyzed based on the measured data. The results show that the fluctuation of the levitation gap was affected by load and stiffness, and the law was consistent with the simulation results. The increase in load or the decrease in beam stiffness would lead to an increase in vertical deflection and vibration of the track beam. However, the train could still maintain good levitation performance under the above extreme conditions, which verified the reliability of the levitation system and the correctness of the simulation model. The conclusion of this paper can provide a reference for the design of the levitation system and track line of medium-and-low-speed maglev train.

Study on Dynamic Response of Straddle-Type Monorail Vehicle with Single-Axle Bogie Under Curve Condition

This paper is concerned with the dynamic response of straddle-monorail with single-axle bogie under curve condition. A 15 degrees-of-freedom(DOF) dynamic model is established for straddle-type monorail vehicle with single-axle bogie, which consists driving wheels, steering wheels and stabilizing wheels. The motion equations of the straddle-type monorail vehicle are derived using the Lagrange's equation, and the wheel-rail contact model and the curving track beam model are created. Compared with the test results, the accuracy of the method is verified. Finally, the influence of curve radius, curve superelevation rate, number of passengers and stiffness of driving wheels on dynamic response is discussed.

Research on Vehicle-Bridge Vertical Coupling Dynamics of Monorail based on Multiple Road Excitations

In order to study the vertical dynamic behavior of the monorail-bridge system, the vehicle-bridge coupling dynamic equation and train simulation model are established based on the principle of dynamics; the train simulation model is established based on the multi-body dynamics; the track model is established based on the finite element theory, and the compression deformation of PC beam and the effect of finger band on train are equivalent to load spectrum on train axle by means of dynamic equivalence principle, and finally, the train-track interaction model is established; the vertical vibration of the train before and after adding the influence of the compressive deformation of the track beam is simulated and calculated respectively, the results show that the influence of the compressive deformation of the track beam on the vertical vibration of the train is significant, and the simulation data under multiple road excitations are very close to the real value.