Effects of Track Elasticity on Wheel-Rail Dynamic Performance of Heavy Haul Railway

2015 ◽  
Vol 744-746 ◽  
pp. 1249-1252 ◽  
Author(s):  
Yong Zeng
Keyword(s):  
Lateral Displacement ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Vertical Force ◽  
Heavy Vehicles ◽  
Derailment Coefficient ◽  
Heavy Haul ◽  
Dynamics Models ◽  
Heavy Haul Railway ◽  
The Impact

Two vehicle-track dynamics models on heavy haul railway are established in two conditions of rigid track and elastic track. And the impact of track elasticity on the wheel-rail dynamics performance was analyzed using models. The results show that the critical speed of heavy vehicles and wheel-rail dynamic indexes, such as wheel-rail lateral force and wheel-rail vertical force decreased on elastic track compared with rigid track. However, other dynamic indexes, including derailment coefficient and lateral displacement of wheelsets increased on elastic track. And the wheel-rail wear indexes are some differences on two tracks.

scholarly journals Influence of Full-Life Cycle Wheel Profile on the Contact Performance of Wheel and Standard Fixed Frog in Heavy Haul Railway

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
He Ma ◽  
Jinming Zhang ◽  
Jun Zhang ◽  
Tao Tao Jin ◽  
Chun Yu Song
Keyword(s):  
Contact Force ◽  
Lateral Displacement ◽  
Dynamic Interaction ◽  
Von Mises Stress ◽  
Static Contact ◽  
Heavy Haul ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Von Mises ◽  
Heavy Haul Railway

Wheel wear is unavoidable, which affects the contact performance of the wheel and rail. This article explores the effects of wheel profile wear on the static contact and dynamic interaction between wheel and standard fixed frog in heavy haul railway. The coupling dynamic models of the vehicle-fixed frog system are established to calculate the change regulation of displacement, contact force, and acceleration when a vehicle passes through the standard fixed frog at a speed of 50 km/h in the facing move in the diverging line. Besides, the finite element models of wheel and standard fixed frog at key positions are developed to simulate the contact patch and distribution of von Mises stress in the regions of the wheel-fixed frog. Compared with the standard profile, the maximum lateral displacement of the worn profile can be reduced by up to 9 mm. The vertical contact force can be reduced from 750 kN to 320 kN, and the decrease is 57.3%. The von Mises stress could decrease up to 34% compared with the standard. And the results show that the wheel profile wear changes the positions of the wheel-rail contact points along the longitudinal direction and affects the dynamic interaction of vehicle and standard fixed frog. For the measured worn wheel profiles in this article, profile wear relieves the dynamic responses and it is good for the nose rail.

Dynamic behavior of a polyurethane foam solidified ballasted track in a heavy haul railway tunnel

2018 ◽  
Vol 22 (3) ◽  
pp. 751-764 ◽  
Author(s):  
Xiaopei Cai ◽  
Yanglong Zhong ◽  
Xiaocheng Hao ◽  
Yanrong Zhang ◽  
Rixin Cui
Keyword(s):  
Elastic Modulus ◽  
Dynamic Behavior ◽  
Polyurethane Foam ◽  
Load Reduction ◽  
Vibration Acceleration ◽  
Wheel Load ◽  
Derailment Coefficient ◽  
Ballasted Track ◽  
Heavy Haul ◽  
Heavy Haul Railway

Dynamic behavior of a new type of track using the polyurethane foam solidified ballast in heavy haul railway tunnels is comprehensively investigated in this study. First, a dynamic model of the vehicle–track–tunnel interaction system was developed based on the multi-body system dynamics theory and finite element method. Then, the dynamic effects of the polyurethane foam solidified ballast track on the train and the surrounding infrastructures were calculated and compared to those of the traditional ballasted track. Moreover, the effects of the elastic modulus and the solidified area size of polyurethane foam solidified ballast on the dynamic behavior were analyzed. Results show that, compared to the traditional ballast bed, polyurethane foam solidified ballast decreases the track stiffness and the vibration acceleration of the tunnel, while does not affect the vehicle safety (derailment coefficient and the rate of wheel load reduction). A larger elastic modulus of polyurethane foam solidified ballast has little effects on the wheel–rail interaction and the vibration acceleration of the tunnel, while a smaller modulus results in amplification of the displacements of rails and sleepers. Considering the vehicle–track interaction and tunnel vibration, the optimal elastic modulus of polyurethane foam solidified ballast is suggested to be 60–80 MPa. In addition, smaller solidified area of polyurethane foam solidified ballast presents lower effects on the vibration reduction and rate of wheel load reduction, while larger area leads to a higher derailment coefficient and cost. Therefore, an optimal solidified area size of polyurethane foam solidified ballast with the top width of 0.85 m is recommended.

A Study of Wheel Flange Partial Wear Problem of Heavy Haul Locomotive

2011 ◽  
Vol 204-210 ◽  
pp. 241-244 ◽  
Author(s):  
Wei Hua Ma ◽  
Shi Hui Luo ◽  
Rong Rong Song
Keyword(s):  
Dynamic Model ◽  
Rotation Angle ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Buffer System ◽  
Heavy Haul Train ◽  
Force Transfer ◽  
Heavy Haul ◽  
Brake Force ◽  
Simulation Results

Aimed to wheel flange partial wear problem, the heavy haul train dynamic model was setup, and the coupler and buffer system was setup in detail. The dynamic performance of the train under the longitudinal coupler press force was simulated. The wheel/rail lateral force and wheel flange wear were analyses. Simulation results shown that the front locomotive will suffer a big longitudinal press force for the delay of the brake force transfer; this will lead the rotation of the coupler. The lateral force will apply to the car body at the position of coupler, which was caused by the longitudinal coupler force and the rotation angle of the coupler, then the wheel flange partial wear were induced as a result.

Research on wheel hollow wear and dynamic performance of freight radial bogies

2016 ◽  
Vol 231 (9) ◽  
pp. 1015-1021 ◽  
Author(s):  
Hengli Li ◽  
Fu Li ◽  
Yunhua Huang
Keyword(s):  
Dynamic Simulation ◽  
Field Test ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Wear Properties ◽  
Wheel Wear ◽  
Depth Effect ◽  
Railway Line ◽  
Heavy Haul ◽  
Dynamic Simulation Model

The wheel wear properties of heavy haul bogies running on the Da-Qin railway line were measured. The hollow and asymmetric wear are indicated. The wheel/rail contact geometry relationship was calculated on the basis of the measured wheel profiles. The dynamic simulation model using SIMPACK software for C80BF Gondola with ZK7 radial bogie and C80B gondola with ZK6 cross brace bogie was established. The hollow depth effect on wheelset attack angle and lateral force was quantified. According to the actual conditions of Da-Qin railway line, the hollow wear was predicted using a numerical method. Based on these results, the hollow wear maintenance standard was recommended. Finally, a field test for asymmetric hollow wear was described.

scholarly journals Influence of Wheel Profile Wear Coupled with Wheel Diameter Difference on the Dynamic Performance of Subway Vehicles

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
H. X. Li ◽  
A. H. Zhu ◽  
C. C. Ma ◽  
P. W. Sun ◽  
J. W. Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Contact Force ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Dynamics Modeling ◽  
Derailment Coefficient ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Wear Index

In view of the coexistence of wheel profile wear (WPW) and wheel diameter difference (WDD) on an actual subway line, a dynamic analysis method based on coupling between WPW and equivalent in-phase WDD was proposed. Based on the measurements from a subway vehicle in operation on this line, dynamics modeling and calculations were performed for a single carriage of this vehicle. Later, the interaction between the effects of WPW and equivalent in-phase WDD on the vehicle dynamic performance was analyzed, and the dynamic response in the presence of coupled damage was compared between the outer and inner wheels. Furthermore, the difference in the dynamic response caused by different positions of the larger-diameter wheels (i.e., on the inner track or outer track) was analyzed for the case where equivalent in-phase WDD occurred between the front and rear bogies. The results show that when the vehicle ran on a straight line, the coupling between WPW and WDD reduced the vehicle’s stability but improved its ride comfort. When the vehicle traveled on a curved line, it showed reductions in the lateral wheel/rail contact force, derailment coefficient, axle lateral force, and wear index if the outer wheels had a larger diameter. As a result, the deterioration of the vehicle’s dynamic performance due to the increasing degree of WPW slowed down, and its curve negotiation performance improved. Meanwhile, the outer wheels had significantly greater lateral wheel/rail contact force, derailment coefficient, and wear index compared to the inner wheels. When a −1 mm WDD was coupled with the worn wheel profile for 14 × 104 kilometers traveled, the dynamic performance indexes of the vehicle were close to or even exceeded the corresponding safety limits. The findings can provide technical support for subway vehicle maintenance.

scholarly journals Experimental Investigation on the Vibration Reduction Characteristics of an Optimized Heavy-Haul Railway Low-Vibration Track

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Zhiping Zeng ◽  
Jundong Wang ◽  
Huatuo Yin ◽  
Shiwen Shen ◽  
Abdulmumin Ahmed Shuaibu ◽  
...  
Keyword(s):  
Impact Load ◽  
Vibration Reduction ◽  
Time History ◽  
Economic Benefits ◽  
Impact Excitation ◽  
Vibration Period ◽  
Time Frequency ◽  
Heavy Haul ◽  
Heavy Haul Railway ◽  
The Impact

Heavy-haul railway has been developed rapidly in many countries in the world due to its great social and economic benefits. One of the key technologies for heavy-haul railway is the reduction of vibration on the track structures and its surrounding due to impact load induced by the train in service. The vibration behaviors of two kinds of low-vibration track (LVT) systems for heavy-haul railway are investigated in this paper. Firstly, two indoor full-scale low-vibration track models (new LVT and traditional LVT), which include rail, fastener, bearing block, rubber boot, track slab, and foundation base, were constructed according to design drawings. Secondly, the vibration responses of the different track components under the impact excitation of a dropping wheelset were measured. Thirdly, the time-domain characteristics of each track component of the two LVTs were compared by the acquired vibration time-history curves. Finally, the frequency-domain distribution was analyzed, and the vibration reduction performance was evaluated by the comprehensive time-frequency analysis results. The results show the new LVT has lower vibration acceleration, shorter duration of vibration period, lower vibration frequency of track components, and most importantly an obvious vibration reduction effect on the ground. The research results are useful to further optimize the design of LVT to reduce the vibration under train impact load.

scholarly journals MODEL-BASED ASSESSMENT OF LONGITUDINAL DYNAMIC PERFORMANCE AND ENERGY CONSUMPTION OF HEAVY HAUL TRAIN ON LONG-STEEP DOWNGRADES

Transport ◽  
2019 ◽  
Vol 34 (3) ◽  
pp. 250-259
Author(s):  
Jin Shi ◽  
Shujing Ren ◽  
Mengran Zhang
Keyword(s):  
Energy Consumption ◽  
Dynamic Performance ◽  
Analytical Tool ◽  
Longitudinal Dynamic ◽  
Heavy Haul Train ◽  
Heavy Haul ◽  
Longitudinal Profiles ◽  
Heavy Haul Trains ◽  
Heavy Haul Railway ◽  
Central South

Longitudinal dynamics performance and energy consumption of heavy haul train should be considered in the design of heavy haul railway profile of long-steep downgrades. A quantitative analytical tool is developed to assess the longitudinal dynamic performance and energy consumption of heavy haul trains with large axle loads on grades with different longitudinal profiles, including a longitudinal dynamic model of the train and a method of calculating the energy consumption during the operation of heavy haul train. The model is then preliminarily validated by the data of coupler force collected in two comprehensive tests. Finally, the proposed analytical tool is used to assess the designed longitudinal track profile of a long-deep downgrade segment of the central south heavy haul railway of Shanxi (China).

Influence of asymmetric out-of-roundness coupled with wear of subway wheels on vehicle dynamics

2020 ◽  
pp. 095440972096224
Author(s):  
Aihua Zhu ◽  
Hongxiao Li ◽  
Jianwei Yang ◽  
Qiang Li ◽  
Si Yang ◽  
...  
Keyword(s):  
Contact Force ◽  
Vehicle Dynamics ◽  
Dynamic Performance ◽  
Great Influence ◽  
Stability Index ◽  
Lateral Force ◽  
Vertical Vibration ◽  
Dynamics Model ◽  
Derailment Coefficient ◽  
Vertical Contact

Out-of-roundness and tread wear are common types of damage to subway wheels, which greatly affect the dynamic performance of subway vehicles. In light of the coupling and asymmetry of out-of-roundness and tread wear found in real-world subway wheels, an analysis method that considers asymmetric out-of-roundness coupled with tread wear was proposed for vehicle dynamics. A vehicle dynamics model featuring asymmetric out-of-roundness coupled with tread wear was used to investigate the influences of asymmetric wheel damage and coupled damage on the dynamic performance of the vehicle system. The vehicle’s dynamic performance was simulated under different conditions, including asymmetric out-of-roundness and symmetric out-of-roundness, uncoupled damage and coupled damage, asymmetric coupled damage and symmetric coupled damage. Then the estimated data was compared against the measured data. The study finds that the vertical wheel/rail contact force, lateral wheel/rail contact force, derailment coefficient and wheel unloading rate increased in the case of asymmetric out-of-roundness. In the presence of coupled damage, the degree of tread wear had a relatively great influence on the lateral wheel/rail contact force, axle lateral force, and derailment coefficient, but had little influence on the vertical contact force. Compared to symmetric coupled damage, asymmetric coupled damage had a greater influence on peak vertical vibration acceleration and stability index, and their values are closer to the measured values in the case of asymmetric coupled damage. This suggests that the dynamics model that considers asymmetric out-of-roundness coupled with tread wear can provide more accurate results as guidance on the maintenance and overhaul of subway wheels.

Studies on Related ms Magnitude Rate Models in Triangular Wave Unloading Section of Calcium Medium-Fine Sandstone

2010 ◽  
Vol 152-153 ◽  
pp. 164-170
Author(s):  
Jie Liu ◽  
Jian Lin Li ◽  
Ying Xia Li ◽  
Shan Shan Yang ◽  
Ji Fang Zhou ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Strain Curve ◽  
Experimental System ◽  
Constant Term ◽  
Lag Time ◽  
Vertical Force ◽  
Time Segment ◽  
Triangular Wave ◽  
Apparent Modulus ◽  
The Impact

Specific to the improvement in the present research of mechanical response under cyclic loading, this paper, taking the calcareous middle- coarse sandstone as the research subject and the RMT-150C experimental system in which data is recoded by ms magnitude as the platform, develops several related models concerning the unloading rate of triangle waves. The unloading process is divided into lag time segment and non-lag time segment, with criterions and related parameters provided as well. The term apparent elastic modulus is defined. The test data analysis shows that there exist a linear relationship between the apparent modulus and instant vertical force before load damage in non-lag time segment. On the preceding basis, a rate-dependent model of triangular wave un-installation section in non-lag time segment is established. Due to the inability of the loading equipment to accurately input the triangle wave, the average loading rate is amended and a constant term is added into it. The model is proved to be reliable, as the predicted value of the deformation rate and the stress strain curve coincides with measured value. At the same time, the impact of the lag time is pointed out quantitatively and a predication model of lag time segment is set up.

Lateral obstacle avoidance control based on driving behavior recognition of the preceding vehicles in adjacent lanes

2020 ◽  
Vol 68 (10) ◽  
pp. 880-892
Author(s):  
Youguo He ◽  
Xing Gong ◽  
Chaochun Yuan ◽  
Jie Shen ◽  
Yingkui Du
Keyword(s):  
Obstacle Avoidance ◽  
Lateral Displacement ◽  
Longitudinal Velocity ◽  
Driving Behavior ◽  
Lateral Acceleration ◽  
Lateral Motion ◽  
Behavior Recognition ◽  
Dynamic Surface ◽  
Lane Changing ◽  
The Impact

AbstractThis paper proposes a lateral lane change obstacle avoidance constraint control simulation algorithm based on the driving behavior recognition of the preceding vehicles in adjacent lanes. Firstly, the driving behavior of the preceding vehicles is recognized based on the Hidden Markov Model, this research uses longitudinal velocity, lateral displacement and lateral velocity as the optimal observation signals to recognize the driving behaviors including lane-keeping, left-lane-changing or right-lane-changing; Secondly, through the simulation of the dangerous cutting-in behavior of the preceding vehicles in adjacent lanes, this paper calculates the ideal front wheel steering angle according to the designed lateral acceleration in the process of obstacle avoidance, designs the vehicle lateral motion controller by combining the backstepping and Dynamic Surface Control, and the safety boundary of the lateral motion is constrained based on the Barrier Lyapunov Function; Finally, simulation model is built, and the simulation results show that the designed controller has good performance. This active safety technology effectively reduces the impact on the autonomous vehicle safety when the preceding vehicle suddenly cuts into the lane.

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