Delft University of Technology
A new small-scale test rig for the wheel-rail contact studies
Naeimi, Meysam; Li, Zili; Dollevoet, Rolf
Publication date
2016
Document Version
Submitted manuscript
Citation (APA)
Naeimi, M., Li, Z., & Dollevoet, R. (2016). A new small-scale test rig for the wheel-rail contact studies.
Poster session presented at Joint Rail Conference, Columbia, United States.
Important note
To cite this publication, please use the final published version (if applicable).
Please check the document version above.
Copyright
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons. Takedown policy
Please contact us and provide details if you believe this document breaches copyrights. We will remove access to the work immediately and investigate your claim.
This work is downloaded from Delft University of Technology.
Railway Engineering Group
Faculty of Civil Engineering and Geosciences
A new small-scale test rig for the wheel-rail contact studies
Meysam Naeimi, Zili Li, Rolf Dollevoet
Railway Engineering Group, Faculty of Civil Engineering, Delft University of Technology
Emails:
m.naeimi@tudelft.nl z.li@tudelft.nl
r.p.b.j.dollevoet@tudelft.nl
High costs of the rolling contact fatigue problem in the wheel and rail materials Unclear root causes of rail squats Uncertain relations between the microstructural and mechanical effects Difficulties in field tests/uncertainties in numerical/theoretical modelling Lack of similarity of tests to the reality No available test setup to simulate the impact-induced RCF
Motivations to build a new rig
Step2: Which operational mechanism?
Design process of the new setup
Step3: Dimensional/scale analysis
Figure 1. Label in 24pt Calibri.
From the field to the Lab
Step1: Literature survey on existing rigs
Examples for the Full-scale
test rigs
Existing test rigs for RCF investigations in wheel-rail 3- Full-size wheel-on-straight rail Full–scale setups Reduced–scale test rigs 1- Full-size vehicle/ bogie rigs 2- Full-size wheel-on-roller 4- Twin discs 5- Scaled wheel on rail track ring
6- Scaled wheel on straight track Examples for the Small-scale rigs Variables/
parameters Variable notation
Units Scale
notation Iwnicki(1998) Chollet(1986) Jaschinski (1999) Current study
Distance L m ϕL 1/N 1/N 1/N 1/N
Cross section A m2 ϕA 1/N2 1/N2 1/N2 1/N2
Volume Vol. m3 ϕVol 1/N3 1/N3 1/N3 1/N3
Moment of inertia I m4 ϕI 1/N 4 1/N4 1/N4 1/N4 Mass M kg ϕM 1/N3 1/N3 2/N3 1/N3 Force F N ϕF 1/N4 1/N2 2/N3 1/N2 Moment T Nm ϕT 1/N 5 1/N3 2/N4 1/N3 Stress σ N/m2 ϕσ 1/N 2 1 2/N 1 Strain ε None ϕε 1/N 1 1 1 Stiffness K N/m ϕK 1/N3 1/N 2/N2 1/N Damping C N.s/m ϕC 1/N3 1/N2 2/N5/2 1/N2 Frequency f Hz ϕf 1 N N1/2 N Time t s ϕt 1 1/N 1/N1/2 1/N Velocity V m/s ϕV 1/N 1 1/N1/2 1
Step4: Finite element modelling
1 MN MX XY Z -.582741-.412157-.241572-.070988.099596.27018.440765.611349.781933.952517 NOV 20 2013 12:32:56 NODAL SOLUTION STEP=1 SUB =2 FREQ=4598.34 UZ (AVG) RSYS=0 DMX =1.01084 SMN =-.582741 SMX =.952517
A spinning frame structure on a ring track bed fixed on the ground
Including multiple (four) wheel components Having a rail-track ring with all components Flexible scale from 1/5 (basic) to 1/7 Similarity in dynamic and impact loading conditions and rolling contact behaviours Similarity in stress-strain behaviours by using real materials of the wheel and rail Adjustable loading conditions, driving and braking torques, frictional behaviours Flexible rolling angle and creep forces
Step5: Fatigue similarity analysis
Step6: Finalizing the concept design
From concept design to the real setup
Static models Dynamic models 0.5 0.6 0.7 0.8 0.9 1 0 0.5 1 1.5 2 2.5 3 Normalized time C o n ta c t fo rc e r a ti o Actual railway 1:5-scaled test rig0 0 200 400 600 800 1000 1200 1400 -2 0 2 N orm al pressure (M Pa) Latera l (mm) Long itudinal (mm) -100.0 -6. 250 87. 50 181.3 275.0 368.8 462.5 556.3 650.0 743.8 837.5 931.3 1025 1119 1213 1306 1400 Some results
Test duration with
the test rig (hours) 1 6 12 24 48 72 96 120
Number of wheel cycles 69,198 415,186830,3731,660,7463,321,4914,982,2376,642,982 8,303,728 Number of rail contact cycles 12,732 76,394 152,789 305,577 611,154 916,732 1,222,309 1,527,886 Eq. tonnage (MGT) 0.25 1.53 3.06 6.11 12.22 18.33 24.45 30.56 The final concept design Detailed design of the new setup The final built setup in the Lab, TU Delft
Joint Rail Conference, JRC2016, Columbia Marriott, Columbia, South Carolina
Step3: Perform a dimensional analysis and determine the proper scaling strategy for the new rig Step2: Determine the operational mechanism of
the new test rig by evaluating various methods Step1: Literature survey on available setups for wheel-rail contact experiments
Step4: Finite element analysis of the downscale test rig to finalize the concept design and dimensions
Step5: Compare fatigue mechanism and cyclic behaviour of the new test rig with the real system
Step6: Perform the detailed mechanical and electrical design of the setup → manufacture the new test rig
