Review Reports

Round 1

Reviewer 1 Report (Previous Reviewer 1)

When reviewing the article, which was supplemented by the authors, I found several errors. In the introduction, the text in verses 77-90 should be deleted, because in verses 90-103 it is identical! In verses 106-107 the authors write "DWS technology will be used for further research...." and then in line 411 the authors write: "- the lubricant material was examined using the DWS technology", unfortunately I do not see any DWS tests performed, so it should be assumed that the research has not been done. Other corrections are acceptable. There are two dots at the end of line 164. This should be corrected. Also, the statement in the summary "high frequencies" for 100 Hz tests is incorrect. You can call higher frequencies, not high frequencies. High frequencies are in DWS tests, of several hundred Hz.

I asking the authors to standardize the names of technical expressions used in the article. Consultation with native speaker required.

Author Response

Hello.

We made corrections to the article according to the comments and recommendations. Answer to the review in the attached file.

Best wishes, authors

Author Response File: Author Response.pdf

Reviewer 2 Report (New Reviewer)

- please review your introduction and discussion portion and remove generic descriptions 
- emphasize on why the results you show or their interpretation is different
- what are the implications of 

 

The language can be improved for scientific coherence. 

Author Response

Hello.

We made corrections to the article according to the comments and recommendations. Answer to the review in the attached file.

Best wishes, authors

Author Response File: Author Response.pdf

Reviewer 3 Report (New Reviewer)

The rheological properties of lubricants are always necessary to be known before we could predict its performances in tribological contacts. This research sets a good example. There are several comments:

1. In sec. 4.3, there are many choices of mathematical models. It is suggest to give a table to summarize the possible choices by showing the mathematical expressions.

2. The lubricant is targeted to the application of bridge bearings. Is it a continuous rotating bearing or in other types of motion? What's the damage mode of it? e.g. fretting? What is the material of the tribo-pair? Is it metal-to-metal contact? It is suggested to give an introduction with details of such application. Because if it is not doing continuously sliding motion, perhaps tribo-chemistry and other aspects of the lubricants may play an important role other than the rheological behavior.

3. There are some typos in the manuscripts. Please check carefully. 

Author Response

Hello.

We made corrections to the article according to the comments and recommendations. Answer to the review in the attached file.

Best wishes, authors

Author Response File: Author Response.pdf

Reviewer 4 Report (New Reviewer)

The paper presents a research on interesting possible approaches for evaluation of viscoelasticity of a grease, which, as a semisolid material, may be subject to solid or fluid theory. It comes with an important experimental part but the most valuable research is the comparison/combination of fluid/solid theory.

Do not use the term paste lubricant. The correct term is grease and Title should be changed

The Introduction should emphasize on the use of the two approaches based on Maxwell body model. Some are already presented in the following chapters. The References list is too long.  

At the first reading, the paper is creating a little confusion. It is confusing calling the same parameter: strain rate, velocity gradient, shear rate, frequency (Lines 225, 294, 302, 311, 334…). Shear rate is the usual term in tribology.

The paper should start with a discussion on possible use of solid theory or high viscosity fluid (melted metals) theory on the case of grease. Also, the experimental equipment is designed for fluids.

The paper also needs some minor clarifications:

Lines 250-252 – Please rephrase: I presume that 0.1% is the value of the strain, as deformation per length. The term sample deformation is also wrong. The term deformation is wrongly used all over the paper.

Line 252, 312 - “steps of 2 °C per minute”. 2 °C per minute is a speed (rate) not a step. Is it a rate of 2 °C per minute, or one measurement at each step of 2 °C?

Author Response

Hello.

We made corrections to the article according to the comments and recommendations. Answer to the review in the attached file.

Best wishes, authors

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report (New Reviewer)

accept

Reviewer 4 Report (New Reviewer)

Paper good for publishing

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

The article presents very interesting results of rheological tests of lubricants, but requires some significant corrections. The introduction does not sufficiently present the state of knowledge in the discussed subject of research. There is no description of the results of rheological tests of lubricants using the DWS technique conducted by other scientists (e.g. Mr. Kozdrach articles). This technique enables testing over a wide frequency range. Conducting tests in the range of 0.01-100 Hz does not provide enough information about the behavior of lubricants. It is necessary to perform tests using the DWS technique, and several dozen such devices are available in the world. Performing tests on such devices will make it possible to understand the behavior of lubricants in a wide range of frequencies and temperatures. If scientists do not have such a device, please find laboratories and perform such tests. The optical rheometer from LSInstruments offers more possibilities. Insufficient data analysis, I see no explanation as to why these results were obtained and not others, and this should be the quintessence of any scientific article! The summary should also be corrected, the conclusions from the conducted research are insufficient. The revised article should be re-evaluated by the reviewers.

The article contains many stylistic errors, that make it difficult to understand the text. The text must be analyzed by a native speaker.

Reviewer 2 Report

 The paper is advised to be declined based on the following reasons：

（1）The abstract's structure fails to meet the journal's requirements.

（2）The paper lacks a comprehensive review of the current research status both domestically and internationally, in accordance with its research objectives.

（3）The author conducted only rheological tests on the lubricant and subsequently fitted it with two models. However, the paper lacks innovation and depth in its analysis.

 

（4）No valuable conclusions can be found.

Minor editing of English language required