Influence of Rail Cant on Wheel-Rail Contact Relationship and Dynamic Performance in Curves for Heavy Haul Railway

Rail cant is one of the most important track geometry parameters, which can change the wheel-rail contact relationship and then influence the dynamic interaction. Static contact geometry parameters for 75kg/m rail in contact with LM wheel tread under different rail cants are analyzed on the basis of the wheel-rail spatial contact geometry algorithm. A train (multi-vehicle)-track coupling dynamic model is established with the help of the software Universal Mechanism (UM), and dynamic performances of train-track system in curves are compared under different rail cants. The results indicate that: (1) flange contact is less likely to occur under 1/20 rail cant, which will reduce uneven wear of wheel/rail tread. (2) In the single-point contact range, when the rail cant increases from 1/40 to 1/20, the corresponding rolling radius difference, contact angle parameter, equivalent conicity and equivalent contact angle parameter all increase, which means the self-centring capacity of wheelset is enhanced and the wheel-rail relationship is improved. (3) When the train passes curves, the increase of rail cant from 1/40 to 1/20 can reduce the wheel-rail dynamic interaction and wear. Besides, the wheel-rail contact area may become bigger, which is conductive to reducing contact stress and contact fatigue failures. The results can provide reference for the design of rail cant of heavy haul railway.

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

Shock and Vibration ◽

10.1155/2020/8866692 ◽

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.

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Reducing rail side wear on heavy-haul railway curves based on wheel–rail dynamic interaction

Vehicle System Dynamics ◽

10.1080/00423114.2014.906633 ◽

2014 ◽

Vol 52 (sup1) ◽

pp. 440-454 ◽

Cited By ~ 28

Author(s):

Wanming Zhai ◽

Jianmin Gao ◽

Pengfei Liu ◽

Kaiyun Wang

Keyword(s):

Dynamic Interaction ◽

Heavy Haul ◽

Heavy Haul Railway

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Investigation on wheel/rail dynamic interaction in heavy-haul railway line with hanging sleepers

The Dynamics of Vehicles on Roads and Tracks ◽

10.1201/b21185-162 ◽

2016 ◽

pp. 1523-1532

Keyword(s):

Dynamic Interaction ◽

Railway Line ◽

Heavy Haul ◽

Heavy Haul Railway

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Investigation of Track Geometry Defects on a Heavy-Haul Railway Line

Journal of Transportation Engineering Part A Systems ◽

10.1061/jtepbs.0000571 ◽

2021 ◽

Vol 147 (9) ◽

pp. 05021004

Author(s):

Hamid Khajehei ◽

Iman Soleimanmeigouni ◽

Alireza Ahmadi ◽

Arne Nissen ◽

Uday Kumar

Keyword(s):

Track Geometry ◽

Railway Line ◽

Heavy Haul ◽

Heavy Haul Railway

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Rail Profile Wear on Curve and its Effect on Wheel-Rail Contact Geometry

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.779-780.655 ◽

2013 ◽

Vol 779-780 ◽

pp. 655-659

Author(s):

Kai Wei ◽

Rui Ying Chen ◽

Yu De Xu

Keyword(s):

Contact Geometry ◽

Rail Wear ◽

Heavy Haul ◽

The One ◽

Heavy Haul Railway

The paper has carried out continued tests on a curve of a heavy haul railway in China for its rail profiles. Based on the data, the paper has counted the development of the rail profile wear, and then analyses the influence of wheel-rail contact geometry on the rail profile wear. The results show that the wear of high rails develops around the rail corners, while the one of low rails around the rail top. The development of the rail wear speeds up after the transport mass passes 210MGT. The wheel-rail contact geometry deteriorates when the transport mass grows up to 60MGT and lower than 210MGT.

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Controlling porosity and density of nanocellulose aerogels for superhydrophobic light materials

TAPPI Journal ◽

10.32964/tj17.03.145 ◽

2018 ◽

Vol 17 (03) ◽

pp. 145-153 ◽

Cited By ~ 1

Author(s):

Chengua Yu ◽

Feng Wang ◽

Shiyu Fu ◽

Lucian Lucia

Keyword(s):

Contact Angle ◽

Freeze Drying ◽

Engine Oil ◽

High Porosity ◽

Water Mixture ◽

Waste Engine Oil ◽

Hydrophobically Modified ◽

Static Contact ◽

Oil Water ◽

Hydrophobic Material

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.

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Biomimetic Approach for the Elaboration of Highly Hydrophobic Surfaces: Study of the Links between Morphology and Wettability

Biomimetics ◽

10.3390/biomimetics6020038 ◽

2021 ◽

Vol 6 (2) ◽

pp. 38

Author(s):

Quentin Legrand ◽

Stephane Benayoun ◽

Stephane Valette

Keyword(s):

Contact Angle ◽

Ginkgo Biloba ◽

Contact Angle Hysteresis ◽

Contact Angles ◽

Textured Surfaces ◽

Replication Process ◽

Wetting Behavior ◽

Static Contact ◽

Biomimetic Approach ◽

Highly Hydrophobic

This investigation of morphology-wetting links was performed using a biomimetic approach. Three natural leaves’ surfaces were studied: two bamboo varieties and Ginkgo Biloba. Multiscale surface topographies were analyzed by SEM observations, FFT, and Gaussian filtering. A PDMS replicating protocol of natural surfaces was proposed in order to study the purely morphological contribution to wetting. High static contact angles, close to 135∘, were measured on PDMS replicated surfaces. Compared to flat PDMS, the increase in static contact angle due to purely morphological contribution was around 20∘. Such an increase in contact angle was obtained despite loss of the nanometric scale during the replication process. Moreover, a significant decrease of the hysteresis contact angle was measured on PDMS replicas. The value of the contact angle hysteresis moved from 40∘ for flat PDMS to less than 10∘ for textured replicated surfaces. The wetting behavior of multiscale textured surfaces was then studied in the frame of the Wenzel and Cassie–Baxter models. Whereas the classical laws made it possible to describe the wetting behavior of the ginkgo biloba replications, a hierarchical model was developed to depict the wetting behavior of both bamboo species.

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Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sensors ◽

10.3390/s21113609 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3609

Author(s):

Mykola Sysyn ◽

Michal Przybylowicz ◽

Olga Nabochenko ◽

Lei Kou

Keyword(s):

High Speed ◽

Experimental Studies ◽

Dynamic Interaction ◽

Theoretical Research ◽

Rolling Stock ◽

Monitoring Methods ◽

Beam Dynamic ◽

Track Geometry ◽

Data Driven Approach ◽

Support Conditions

The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.

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