A numerical model to predict three-dimensional interaction dynamic of low-medium-speed maglev vehicle–guideway bridge system

2021 ◽  
pp. 095440972199655
Author(s):  
Fenghua Huang ◽  
Bin Cheng ◽  
Nianguan Teng
Keyword(s):  
Numerical Model ◽  
Dynamic Responses ◽  
Vehicle Speed ◽  
3D Interaction ◽  
Frequency Responses ◽  
Maglev Vehicle ◽  
Coupling System ◽  
Medium Speed ◽  
Vibration Responses ◽  
Bridge System

This paper established a numerical model to investigate the dynamic behavior of LMS (low-medium-speed) maglev vehicle-guideway bridge coupling system. In this model, the vehicle was simulated as a 3D (3-dimensional) multi-rigid body with 45 DOFs (degree of freedoms), and the guideway bridge was built through finite element method. Two-dimensional magnet-guideway relationship was introduced, and the control strategies of active suspension control based on PID controller and passive guidance control were employed to reflect the vehicle-guideway interaction. A solution program was then developed to solve the vehicle-guideway interaction problem. Through case study, the vibration responses achieved from 3D interaction model were compared to those from corresponding 2D (2-dimensional) model. Besides, the effects of pier and guideway irregularity on dynamic responses of vehicle-guideway bridge coupling system were investigated, and the frequency responses of vehicle and guideway were also analyzed. The result shows that ignoring the pier modeling or guideway irregularity would significantly undervalue the vibration responses of maglev vehicle-guideway bridge interaction system. The frequency responses indicate that the vibrations of vehicle-guideway bridge system are significantly related to the geometric dimensions of maglev vehicle, especially the distance between two magnet units. Finally, parametric study was carried out to determine the effects of key parameters (i.e., vehicle speed and natural frequency of guideway) on guideway responses.

Dynamic Performance of the LMS Maglev Train–Track–Bridge System Under Uneven Settlement for Two Typical Bridges

2020 ◽  
pp. 2150006
Author(s):  
Dangxiong Wang ◽  
Xiaozhen Li ◽  
Ziyan Wu
Keyword(s):  
Numerical Model ◽  
Dynamic Performance ◽  
Interaction Model ◽  
Dynamic Interaction ◽  
Dynamic Responses ◽  
Train Track ◽  
Maglev Train ◽  
Medium Speed ◽  
Track Bridge ◽  
Bridge System

To investigate the dynamic performance of the low-to-medium-speed (LMS) maglev train and bridge system under uneven ground settlement, a refined vertical dynamic interaction model of the LMS maglev train–track–bridge system with uneven settlement is proposed. Firstly, the numerical model is verified based on the field test. Secondly, the dynamic performances of the system induced by uneven settlements are numerically analyzed. Furthermore, numerical studies are carried out to investigate the effect of various uneven settlement types, to compare the performances of the two typical bridges, and to assess the contribution of the F-rail in the presence of uneven settlement. The results show that uneven settlement has a significant enlargement effect on the dynamic responses of the car body and levitation module, but a very weak influence on the bridge. Both the patterns of uneven settlement and bridge types significantly affect the dynamic response of the maglev train to various levels. The numerical model excluding the track structure will overestimate the dynamic responses of the levitation module. It is suggested that the dynamic interaction model for the maglev train–track–bridge system be selected to simulate the influence of uneven settlement for better accuracy.

scholarly journals Vehicle Ride Comfort Analysis Based on Vehicle-Bridge Coupled Vibration

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yichang Zhang ◽  
Wusheng Li ◽  
Zhe Ji ◽  
Guichun Wang
Keyword(s):  
Rational Design ◽  
Ride Comfort ◽  
Dynamic Balance ◽  
Dynamic Responses ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupling Vibration ◽  
Multiple Vehicles ◽  
Vibration Responses

The study in this paper aims to evaluate the effects of vehicle-bridge coupled vibration on the vehicle ride comfort. The mechanical model of both vehicle and bridge subsystems and the vibration differential equations are established, respectively, based on the principle of dynamic balance and finite element method. The APDL command stream for iterative calculation is compiled on the ANSYS platform. The method to evaluate the vehicle ride comfort is established according to the criteria in ISO2631-1-1997. The vehicle dynamic responses and ride comfort are analyzed considering different pavement levels while multiple vehicles pass through the cable-stayed bridge. The analysis results indicate that the dynamic responses of vehicles decrease with the improvement of pavement roughness, resulting in the vehicle ride comfort to be better; the dynamic responses of vehicles increase with the increment of vehicle speed or the decrement of vehicle gravity, resulting in the vehicle ride comfort to be worse. The present research results can provide an insight into the rational design of bridge structure so as to reduce the vehicle-bridge coupling vibration responses and improve the ride quality of drivers and passengers.

Coupled dynamic analysis of low and medium speed maglev vehicle-bridge interaction using SIMPACK

2020 ◽  
pp. 095440972092567
Author(s):  
Junxiong Hu ◽  
Weihua Ma ◽  
Shihui Luo
Keyword(s):  
Vertical Vibration ◽  
Dynamic Force ◽  
Vehicle Speed ◽  
Coupled Vibration ◽  
Coupled Dynamic Analysis ◽  
Maglev Vehicle ◽  
Vehicle System ◽  
Medium Speed ◽  
Levitation System ◽  
Multi Body

The low- and medium-speed maglev vehicle generally operates on elevated bridges with a levitation gap of only 8--10 mm, which makes it very sensitive to the vehicle--bridge coupled vibration. To conduct the corresponding modeling and simulation with common dynamics tools, an equivalent processing of the levitation system is required. Using the dynamics software SIMPACK, this paper first introduces the methods of building the multi-body vehicle system, levitation control system and the elastic bridge, respectively, in the SIMPACK railway module, levitation control module and SIMBEAM elastomer module, thus providing a modeling idea for the simulation of the active levitation and operation of low- and medium-speed maglev vehicles through multi-span bridges. It then goes on to simulate and analyze the coupled vibration of a 160 km/h low- and medium-speed maglev vehicle passing through 25 m + 25 m double-span continuous bridges. The research results show that the modeling method introduced in this paper can simulate the low- and medium-speed maglev vehicle--bridge coupled vibration phenomenon, which can be affected significantly by the low-order frequency of the elastic bridge, and can also be intensified under the bridge end impact when the vehicle enters and leaves the bridge. As the running speed of the vehicle increases and the dynamic force increases, the vertical vibration amplitudes of the elastic bridge mid-span, the car body as well as the levitation frame approximate a linear fitting with the vehicle speed. The variation amplitudes of the levitation gap and of the electromagnet current approximate a quadratic fitting with the vehicle speed.

scholarly journals Gust Wind Effects on Stability and Ride Quality of Actively Controlled Maglev Guideway Systems

2017 ◽  
Vol 2017 ◽  
pp. 1-23 ◽  
Author(s):  
Dong-Ju Min ◽  
Soon-Duck Kwon ◽  
Jong-Won Kwark ◽  
Moon-Young Kim
Keyword(s):  
Wind Speed ◽  
Magnetic Levitation ◽  
Influential Factor ◽  
Dynamic Responses ◽  
Dominant Factor ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Running Safety ◽  
Maglev Vehicle

The purpose of this paper is to present a framework to analyze the interaction between an actively controlled magnetic levitation vehicle and a guideway structure under gusty wind. The equation of motion is presented for a 30-dof maglev vehicle model consisting of one cabin and four bogies. In addition, a lateral electromagnetic suspension (EMS) system is introduced to improve the running safety and ride quality of the maglev vehicle subjected to turbulent crosswind. By using the developed simulation tools, the effects of various parameters on the dynamic response of the vehicle and guideway are investigated in the case of the UTM maglev vehicle running on a simply supported guideway and cable-stayed guideway. The simulation results show that the independent lateral EMS and associated control scheme are definitely helpful in improving the running safety and ride quality of the vehicle under gusty wind. In the case of the cable-stayed guideway, at low wind speed, vehicle speed is the dominant factor influencing the dynamic responses of the maglev vehicle and the guideway, but at wind speed over 10 m/s, wind becomes the dominant factor. For the ride quality of the maglev vehicle, wind is also the most influential factor.

scholarly journals Lane Departure Warning Estimation Using Yaw Acceleration

2020 ◽  
Vol 11 (1) ◽  
pp. 102-111
Author(s):  
Em Poh Ping ◽  
J. Hossen ◽  
Wong Eng Kiong
Keyword(s):  
Vehicle Dynamics ◽  
Dynamic Responses ◽  
Dynamics Simulation ◽  
Steering Wheel ◽  
Mathematical Representation ◽  
Vehicle Speed ◽  
Lane Departure Warning ◽  
Model Based ◽  
Lane Departure ◽  
Proposed Model

AbstractLane departure collisions have contributed to the traffic accidents that cause millions of injuries and tens of thousands of casualties per year worldwide. Due to vision-based lane departure warning limitation from environmental conditions that affecting system performance, a model-based vehicle dynamics framework is proposed for estimating the lane departure event by using vehicle dynamics responses. The model-based vehicle dynamics framework mainly consists of a mathematical representation of 9-degree of freedom system, which permitted to pitch, roll, and yaw as well as to move in lateral and longitudinal directions with each tire allowed to rotate on its axle axis. The proposed model-based vehicle dynamics framework is created with a ride model, Calspan tire model, handling model, slip angle, and longitudinal slip subsystems. The vehicle speed and steering wheel angle datasets are used as the input in vehicle dynamics simulation for predicting lane departure event. Among the simulated vehicle dynamic responses, the yaw acceleration response is observed to provide earlier insight in predicting the future lane departure event compared to other vehicle dynamics responses. The proposed model-based vehicle dynamics framework had shown the effectiveness in estimating lane departure using steering wheel angle and vehicle speed inputs.

Effect of unsupported sleepers on dynamic behavior of running vehicles and ride comfort index

2021 ◽  
pp. 095440622198937
Author(s):  
Mojtaba Azizi ◽  
Majid Shahravi ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Numerical Model ◽  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Field Test ◽  
Ride Comfort ◽  
Vehicle Speed ◽  
Comfort Index ◽  
Railway Industry ◽  
Flexible Track ◽  
Train Speed

Nowadays, with various advancements in the railway industry and increasing speed of trains, the design of railway tracks and vehicles has become vitally important. One of the frequent problems of ballasted tracks is the existence of unsupported sleepers. This phenomenon occurs due to the lack of ballast underneath the sleepers. Here, a model is presented, in which a flexible track model in a multibody dynamics program is developed, in order to study the dynamic behavior of a vehicle. By utilizing the model, it is feasible to simulate unsupported sleepers on the flexible track including rail, sleeper, and ballast components. In order to verify the results of numerical model, a field test is performed. Findings indicate that, in the case of a single unsupported sleeper through the track, the ride comfort index increased by 100% after increasing the train speed from 30 to 110 km/h. Moreover, when it is needed to have ride comfort index improvement over the uncomfortable level, the vehicle speed should be less than 70 km/h and 50 km/h for tracks with one unsupported sleeper and two unsupported sleepers, respectively.

Influences of Wind Barriers on the Train Running Safety on a Highway-Railway One-Story Bridge

2021 ◽  
pp. 2140009
Author(s):  
Ye Liu ◽  
Yan Han ◽  
Peng Hu ◽  
C. S. Cai ◽  
Xuhui He
Keyword(s):  
Dynamic Responses ◽  
Response Analysis ◽  
Train Track ◽  
Wheel Load ◽  
Wind Barrier ◽  
The Mean ◽  
Wind Pressures ◽  
Track Bridge ◽  
Fluctuating Wind ◽  
Bridge System

In this study, the influences of wind barriers on the aerodynamic characteristics of trains (e.g. a CRH2 train) on a highway-railway one-story bridge were investigated by using wind pressure measurement tests, and a reduction factor of overturning moment coefficients was analyzed for trains under wind barriers. Subsequently, based on a joint simulation employing SIMPACK and ANSYS, a wind–train–track–bridge system coupled vibration model was established, and the safety and comfort indexes of trains on the bridge were studied under different wind barrier parameters. The results show that the mean wind pressures and fluctuating wind pressures on the trains’ surface decrease generally if wind barriers are used. As a result, the dynamic responses of the trains also decrease in the whole process of crossing the bridge. Of particular note, the rate of the wheel load reductions and lateral wheel-axle forces can change from unsafe states to relative safe states due to the wind barriers. The influence of the porosity of the wind barriers on the mean wind pressures and fluctuating wind pressures on the windward sides and near the top corner surfaces of the trains are significantly greater than the influence from the height of the wind barriers. Within a certain range, decreasing the wind barrier porosities and increasing the wind barrier heights will significantly reduce the safety and comfort index values of trains on the bridge. It is found that when the porosity of the wind barrier is 40%, the optimal height of the wind barrier is determined as approximately 3.5[Formula: see text]m. At this height, the trains on the bridges are safer and run more smoothly and comfortably. Besides, through the dynamic response analysis of the wind–train–track–bridge system, it is found that the installation of wind barriers in cases with high wind speeds (30[Formula: see text]m/s) may have an adverse effect on the vertical vibration of the train–track–bridge system.

scholarly journals Road Vehicle-Bridge Interaction considering Varied Vehicle Speed Based on Convenient Combination of Simulink and ANSYS

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Helu Yu ◽  
Bin Wang ◽  
Yongle Li ◽  
Yankun Zhang ◽  
Wei Zhang
Keyword(s):  
Reaction Force ◽  
Sudden Change ◽  
Vertical Direction ◽  
Dynamic Responses ◽  
Force Model ◽  
Vertical Acceleration ◽  
Vehicle Speed ◽  
Road Vehicle ◽  
The Road ◽  
Bridge Model

In order to cover the complexity of coding and extend the generality on the road vehicle-bridge iteration, a process to solve vehicle-bridge interaction considering varied vehicle speed based on a convenient combination of Matlab Simulink and ANSYS is presented. In this way, the road vehicle is modeled in state space and the corresponding motion equations are solved using Simulink. The finite element model for the bridge is established and solved using ANSYS. The so-called inter-history iteration method is adopted to realize the interaction between the vehicle model and the bridge model. Different from typical method of road vehicle-bridge interaction in the vertical direction, a detailed longitudinal force model is set up to take into account the effects of varied vehicle speed. In the force model, acceleration and braking of the road vehicle are treated differently according to their mechanical nature. In the case studies based on a simply supported beam, the dynamic performance of the road vehicle and the bridge under varied vehicle speeds is calculated and discussed. The vertical acceleration characteristics of the midpoint of beam under varied vehicle speed can be grouped into two periods. The first one is affected by the load transform between the wheels, and the other one depends on the speed amplitude. Sudden change of the vertical acceleration of the beam and the longitudinal reaction force are observed as the wheels move on or off the bridge, and the bridge performs different dynamic responses during acceleration and braking.

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