Two Contributions to Rolling Contact Fatigue Testing Considering Different Diameters of Rail and Wheel Discs
, Radim Halama 1,*, Martin Marek 1,2, Michal Šofer 1, Libor Kovář 3 and Petr Matušek 3
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsComments for author File: 
Comments.pdf
Author Response
Dear reviewer, thank you for your review, which helps us to improve our manuscript. The responses to your questions and suggestions are written in the attached PDF file.
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript is interesting, but the novelty should be improved.
1. Equations and Figures in the paper should be improved.
2. In Finite element simulations 3.1.2, why do you use two-dimensional Hertzian theory? Actually, it is three-dimensional issue. In addition, actual wheel-rail rolling contact is not slip friction.
3. In section 3.2.2, what is the aim of this verification? How do you verify the correction of the numerical results?
4. The title of the paper is about rolling contact fatigue, but the paper did not present any experimental results on it.
Comments on the Quality of English LanguageNo comment.
Author Response
Dear reviewer, thank you for your review, which helps us to improve our manuscript. The responses to your questions and suggestions are written in the attached PDF file.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsDear Authors, good evening.
My suggestions for corrections of the manuscript:
1) All equations must be "called" in the text, before the equation;
2) Section 2 (Material and background) should be into Section 1 (Introduction);
3) The manuscript must have a Conclusions section.
Author Response
Dear reviewer, thank you for your review, which helps us to improve our manuscript. The responses to your questions and suggestions are written in the attached PDF file.
Author Response File: Author Response.pdf
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors,
Major remarks:
1. The structure of the paper is not correct, which makes it significantly difficult to read. The structure should be adapted to the publisher's recommendations (Introduction – Materials and Methods – Results – Discussion – Conclusions).
2. The huge parts of the paper seem rather like a report than a scientific paper. I propose the revise the contents of the paper and use section “Discussion”. At the moment, because the paper is consisted of two parts it is difficult to find the meaning of the particular parts of the article.
3. The paper also has many grammar and style problems. Some words seem to be not correct (i.e. - cycling line 19, loosening – 133, etc.), and typos (i.e countor –Figure 12, spline by 50 value – Figure 14, profil – figures 16 and 17, etc.). The paper should be very carefully revised by a native English speaker.
4. Introduction – the literature review with respect to rolling contact fatigue testing should be carried out and reported in the Introduction.
5. Line 71 “For the RCF mechanism, a suitable critical plane approach is applied” – I do not agree with this statement. Generally, such criteria underestimate the fatigue effort in the case of rolling contact fatigue. A much better evaluation is obtained with the application of the criteria based on the integral approach. The Authors should revise this part with respect to the recent literature (not from 2000-2001).
6. Figure 1 - There is missing information about the surface roughness and geometrical tolerances (mainly the wheel thread surfaces). Such information should be also reported.
7. Line 160 – It is reported that the analysis is performed for the case with plastic deformation. Please explain how the Hooke’s law can be applied in such cases with plastic deformations
8. Line 190 – What about axial stresses?
9. Equation 9 – what contact type was assumed – line or elliptical?
10. Figure 4 – Why does contact pressure act at a certain angle to the surface?
11. More information about FE modeling should be provided – type of contact elements, version of solver, properties of the contact solver, material stress-strain curve, method of the validation of the FE model, etc.
12. Figure 6 is unable to read. Different colors for particular curves should be used.
13. Figure 7 – legend should be improved
14. Table 3- What was the criterion of the test finish (Nf = 100000 and 21500 cycles)?
15. Line 294 – How the rotational speed of two motors was controlled and regulated? What was the accuracy of such operations?
16. Line 300-314 – The description of the second test stand is really poor. The CAD drawing with the geometries of the wheels as well as better photographs should be provided.
17. Figures 16 and 17 – The initial profiles should be included.
18. The conclusions are too long.
Kind Regards,
Comments on the Quality of English Language
The paper also has many grammar and style problems. Some words seem to be not correct (i.e. - cycling line 19, loosening – 133, etc.), and typos (i.e countor –Figure 12, spline by 50 value – Figure 14, profil – figures 16 and 17, etc.). The paper should be very carefully revised by a native English speaker.
Author Response
Dear reviewer, please, see attached word file with our responses to your questions.
Author Response File: 
Author Response.docx
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsIt can be accepted now.
Comments on the Quality of English LanguageNo comments.
Author Response
Dear reviewer, thank you for your recommendation to accept our manuscript after the corrections we performed.
Reviewer 4 Report
Comments and Suggestions for AuthorsDear Authors,
Minor remarks:
1. Please correct figure order – Figures 12 and 13 are cited (Line 318 and 323) before Figures 10 and 11 (Line 334, 335).
2. Conclusions: Line 496 “specimens” – please reconsider another word, i.e.: “objects” ?
3. Conclusions “The experimental setup will also be use in the field of pressure force regulation, which will ensure more stable simulated conditions such as the contact pressure or the slip.” – not clear, please precise.
Kind Regards,
Author Response
See attached file.
Author Response File: Author Response.pdf
