Wear Prediction of Curved Switch Rail in High-Speed Turnout and Influence of Wheel and Rail Wear on Vehicle Dynamic Performance
Round 1
Reviewer 1 Report
This paper presents a study on the dynamic behaviour of a high-speed train moving through turnout with different wear levels both in the turnout and the wheels. All data presented in the paper comes from simulations carried out in multibody software. The topic is interesting but the novelty of the paper must be clearly explained. In addition, some relevant information about the turnout and the rolling stock is missing.
I have several concerns about the paper:
1. In line 64 the authors state that “the curved switch rail wear prediction model is developed”. However, the presented work is just an application of the tools available in the Universal Mechanism software. The authors must detail what is the contribution of the paper and what is added to the models already implemented in Universal Mechanism.
2. The authors also state that rigid solid bodies are used to improve calculation efficiency. However, Universal Mechanism is a multibody software, so you need to define rigid solid bodies and no simplifications are made. You could import flexible models from FEM software and perform mixed (rigid-flexible) calculations, but it makes no sense to the addressed problem.
3. In lines 142-144, the authors justify the use of the Kik-Piotrowski theory on the fact that it is faster than CONTACT and ensures accuracy, which is true. But it is also the required model to compute wear evolution in UM.
4. The Archard model used to compute the wear should be explained and cited in the text.
5. Key information about the rolling stock is missing.
a. What are the mass and inertia parameters of the coach, the bogies and the wheelsets?
b. Is there no damping in the longitudinal and lateral directions in the primary suspension?
c. What are the damping parameters of the secondary suspension?
6. What is the meaning of “No.18 high-speed turnout”? Is this the identification number of turnout in a specific route? It is the model number?
7. Regarding the characteristics of the turnout, is it of type swingnose crossing or moveable point frog? What is the maximum speed when taking the fork?
8. The procedure to compute the rail wear isn’t clear to this reviewer. Is the worn profile actually computed by the authors? How do you compute the full worn profile from the wear depth? UM computes the evolution of the wear according to the steps defined by the user and updates the geometry of the rail head. Are you using this?
9. The gauge measuring point should be defined. Are you using the gauge corner wear (W3) as the measuring parameter? It should be explained in the text.
10. The profiles that are shown in Figure 7 exhibit gauge corner wear in all cases, which disagrees with the discussion of the results and Table 4.
11. Regarding Table 4, do the values shown there correspond to the same wear parameter?
12. The computation of the accelerations should be explained too. At which point in which body are you measuring the accelerations?
13. Line 111 states “The UM software is applied […]”. Please, replace “UM” with Universal Mechanism. At least, the first time you mention the software.
14. The first bulleted conclusion is not a conclusion of this work, but a conclusion of works performed by Piotrowski et al.
15. The quality of Figure 6 should be improved.
16. Check numbering in line 375
Minor editing of English language required
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The submitted manuscript deals with the topic of dynamic behavior and derailment safety of a rail vehicle in a turnout and is interesting. The structure of the work is correct, the references are also appropriately selected in terms of quantity, quality and subject matter. The method applied includes correct review of models and tools typically used for similar tasks. The language of the work is very good, although there are isolated glitches. Beside from the above, I recommend changes, corrections and additions listed below before publication.
Line 14: The dynamic model of the vehicle – curved switch rail system based…
Line 18: 50[space]mm
Line 22: curved
Line 29: please replace ‘line’ with ‘track’
Line 35: different reference in text (Wang Smitirupa) and list (Pradhan et al.)
Line 73: The radius of the curved switch rail equals…
Line 78: structure, [comma not fullstop]
Fig 1: measuring the distances between cross sections would improve the value of the picture
Fig 3, 8, 10, 12, 14, 15, 17, 19, 21 please increase size of the description
Equation 1: please explain below what is g(y)
Line 156: ends of what? Of bogie, of car?
Line 159: what is this assumption based on? I feel it needs to be supported with evidence, as head size of the switch rail is severely reduced in size
Line 176: Otherwise, the worn depth calculation is continued...
Line 204: please use alternatives to ‘serious’: pronounced, visible, deeper,…
Line 205-210: different wear rates cause false and various radii of curved switch rail on short distances, which in turn increases dynamic load on rail head
Line 214, 310: The next step is to investigate…
Line 324: intensify [no upper case letter needed]
Line 357-363: I think it is worth adding that derailment coefficient is also a function of velocity
Line 407-409: meaning unclear, please rephrase
Reference 2: Fu[no space here],
Ref 2, 5, 6, 17, 19: please expand to full list of authors instead of ‘et al.’
Ref 20: Gao [no upper case letter needed]
Ref 24: Schmid R, Endlicher K-O, Lugner P.
As stated above, the language of the work is very good, although there are isolated glitches, listed.
Author Response
Please see the attachment.
Author Response File: Author Response.doc
Round 2
Reviewer 1 Report
The authors have answered all my previous questions and amended the paper accordingly. However, after reviewing the improved version of the paper, I have a major concern that must be solved before publishing the paper.
In equations 10, 12 and 13 the authors use Hertz’s theory to compute the normal contact stress and then use this value in the Archard model. In the previous paragraphs, it is stated that the Kik-Piotrowski model is used to compute contact forces, as this is the model implemented in UM to predict rail wear. Please, explain this discrepancy.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 3
Reviewer 1 Report
The authors have answered all my queries.
Author Response
Thank you very much for your valuable comments, which have been very helpful in improving the quality of the paper. Thank you for your guidance. Thank you for your recognition of me.
