Analysis, Modeling and Experimental Study of the Normal Contact Stiffness of Rough Surfaces in Grinding

Round 1

Reviewer 1 Report

Dear Editor,

I am writing to you as a reviewer of the manuscript titled "Analysis, Modeling and Experimental Study of Normal Contact Stiffness of Rough Surface in Grinding" which was submitted to Lubricants with the manuscript ID Lubricants -2657384.

The objective of this paper is to analyze and model the normal contact stiffness of rough surfaces in grinding. The experimental stiffness values were found to be consistent with the fitting stiffness values of the new model established. This verifies the reliability and effectiveness of the new model for the grinding surface. The paper also mentions that the stability of mechanical equipment can be improved by improving grinding precision and reducing the roughness of the joint surface. The work is financially supported by the National Natural Science Foundation of China. Overall, the paper focuses on the analysis, modeling, and experimental study of normal contact stiffness of rough surfaces in grinding. It presents a new model and verifies its reliability through experimental results.

Advantage:

-        The experiment verifies the reliability and effectiveness of the model.

-        The article's detailed analysis of the contact stiffness model considers various factors such as pressure, roughness, and plasticity indices to enhance the understanding of the contact mechanism for rough surfaces.

-        The article highlights the use of dimensionless processing in the model, allowing for easy comparison between various models. This results in better clarity and comparability of the research findings.

Disadvantage:

-        The article has a limited scope as it only focuses on the contact stiffness of rough surfaces in grinding and does not explore other areas of mechanical design or dynamic modeling.

-        The article acknowledges that the new model is an improvement over previous models, but it fails to provide a direct comparison between the two.

-        The article presents findings based on a particular experimental setup and material (304 steel), which may limit the generalizability of the research outcomes to other materials and surface conditions.

Overall, the article provides valuable insights into the contact stiffness of rough surfaces in grinding. However, further research and comparisons with other models are needed to fully evaluate the strengths and weaknesses of the proposed model. Some advice and suggestions are:

- Although the abstract in this paper provides a brief overview of the study's main objectives, methods, and findings, it would be advisable to focus on your study's significance and implications more.

- The Introduction section of this paper effectively introduces the topic, states the objectives and methodology of the study, and provides an overview of the existing literature. It sets the context for the research and establishes its significance. Overall, it is clear and well-written.

- The hypothetical surface section of this paper is comprehensive and well-written, explaining the importance of understanding the contact mechanism of grinding joint surfaces and providing detailed information about the parabolic cylindrical asperity model. The experimental results confirm the model's effectiveness, but it may not fully capture the complex interaction between rough surfaces in real-world scenarios and ignores the interaction between asperities, limiting its applicability in certain contact situations.

- The Normal contact stiffness theoretical and analytical model section of this paper is well-written and provides a thorough analysis of the research topic. However, more attention could be given to discussing the practical applications of the research findings.

- The Experiment section of this paper is clear and well-written. The authors provide a detailed description of the research methods used in the study and explain the rationale behind their choices. However, some technical terms may be challenging for non-experts to understand. Additionally, the section could benefit from more discussion on the limitations of the study and areas for future research.

- The Results and Discussion section of this paper is well-written and informative. The authors provide a clear overview of their research methodology and findings. However, the text could have been organized more clearly, perhaps using subheadings to separate different findings more accurately.

- The conclusion section of this paper provides a comprehensive summary of the research findings and their implications. The disadvantage of the conclusion in this paper is that it does not provide detailed information on the limitations or potential areas for further research. It does not mention any potential drawbacks or challenges that may arise when applying the proposed model in practical applications.

Ultimately, the paper presents a detailed analysis of the contact mechanism of rough bonded surfaces, with a focus on grinding surfaces. However, the paper may be improved by providing more details about the experimental setup and results, and by discussing the limitations and scope of their model. Accordingly, this article may be accepted after the requisite revisions and reassessment.

Thank you for considering my opinion.

Sincerely,

Author Response

Response to Reviewer 1 Comments

We thank the reviewer for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

• The article has a limited scope as it only focuses on the contact stiffness of rough surfaces in grinding and does not explore other areas of mechanical design or dynamic modeling.

Response

Thank you for this comment. This paper only focuses on modeling, and the next step is to focus on exploring other fields of mechanical design or dynamic modeling according to the new model.  

• The article acknowledges that the new model is an improvement over previous models, but it fails to provide a direct comparison between the two.

Response

Thank you for this comment. According to your suggestion, I have made a comparison between the new model and the previous model. For details, please refer to the modification on page 15 of the article.

• The article presents findings based on a particular experimental setup and material (304 steel), which may limit the generalizability of the research outcomes to other materials and surface conditions.

Response

Thank you for this comment. Elastic modulus, Poisson's ratio and hardness determine the mechanical properties of a material. This model also studies the contact stiffness according to the above three characteristics. So this model is still applicable to other metal materials.

• Although the abstract in this paper provides a brief overview of the study's main objectives, methods, and findings, it would be advisable to focus on your study's significance and implications more.

Response

Thank you for this comment. Changes have been made in the summary.

• The Introduction section of this paper effectively introduces the topic, states the objectives and methodology of the study, and provides an overview of the existing literature. It sets the context for the research and establishes its significance. Overall, it is clear and well-written.

Response

Thank you for this comment.

• -The hypothetical surface section of this paper is comprehensive and well-written, explaining the importance of understanding the contact mechanism of grinding joint surfaces and providing detailed information about the parabolic cylindrical asperity model. The experimental results confirm the model's effectiveness, but it may not fully capture the complex interaction between rough surfaces in real-world scenarios and ignores the interaction between asperities, limiting its applicability in certain contact situations.

Response

Thank you for this comment. In this paper, the height distribution function of the asperity is assumed to be Gaussian function, which can effectively deal with the problem of convex and convex inequality.

• The Normal contact stiffness theoretical and analytical model section of this paper is well-written and provides a thorough analysis of the research topic. However, more attention could be given to discussing the practical applications of the research findings.

Response

Thank you for this comment. Your proposal is very good, and the next step will be to study the practical application of the results.

• -The Experiment section of this paper is clear and well-written. The authors provide a detailed description of the research methods used in the study and explain the rationale behind their choices. However, some technical terms may be challenging for non-experts to understand. Additionally, the section could benefit from more discussion on the limitations of the study and areas for future research.

Response

Thank you for this comment. Your proposal is very good, the next step will be to study the limitations of the model and the application of dynamics.

• The Results and Discussion section of this paper is well-written and informative. The authors provide a clear overview of their research methodology and findings. However, the text could have been organized more clearly, perhaps using subheadings to separate different findings more accurately.

Response

Thank you for this comment. Some changes have been made to the content of the paper according to your suggestion.

• - The conclusion section of this paper provides a comprehensive summary of the research findings and their implications. The disadvantage of the conclusion in this paper is that it does not provide detailed information on the limitations or potential areas for further research. It does not mention any potential drawbacks or challenges that may arise when applying the proposed model in practical applications.

Response

Thank you for this comment.According to your suggestion, some improvements have been made to the conclusion of the paper, adding a model comparison study.

Author Response File: Author Response.docx

Reviewer 2 Report

1.     Abstract is lacking the key findings of the work.

2.     Provide a brief overview of the current state of research in the field of grinding and precision machining, including key challenges, advancements, and gaps in knowledge.

3.     Include relevant references to support the importance of understanding the contact mechanism of grinding joint surfaces.

4.     Clarify the specific objectives of the study and how it aims to address the existing gaps or limitations in the field.

5.     Improve resolution of Figures.

6.     Discuss the strengths and weaknesses of each model in terms of their ability to accurately represent the contact mechanism of rough surfaces in grinding.

7.     Highlight any recent developments or alternative models that have been proposed in the literature.

8.     Clearly state how the proposed research differs from or builds upon the existing models and approaches.

9.     Describe the process of analyzing and reconstructing the asperity profile and explain the rationale behind choosing the parabolic asperity model as the basis for the study.

10.  If applicable, mention any software or computational tools used in the study.

11.  Compare the findings with previous models or studies, highlighting similarities, differences, and potential reasons for discrepancies.

Author Response

We thank the reviewers for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

• Abstract is lacking the key findings of the work.

Response

Thank you for this comment. We have made revisions in Abstract .

• Provide a brief overview of the current state of research in the field of grinding and precision machining, including key challenges, advancements, and gaps in knowledge.

Response

Thank you for this comment. We have made revisions in Introduction.

• Include relevant references to support the importance of understanding the contact mechanism of grinding joint surfaces.

Response

Thank you for this comment. These references are included in the article citations.

• Clarify the specific objectives of the study and how it aims to address the existing gaps or limitations in the field.

Response

Thank you for this comment. The research objectives are clarified in the introduction of the article.

• Improve resolution of Figures.

Response

Thank you for this comment. The resolution of the article image has been increased.

• Discuss the strengths and weaknesses of each model in terms of their ability to accurately represent the contact mechanism of rough surfaces in grinding.

Response

Thank you for this comment. The resolution of the article image has been increased.

• Highlight any recent developments or alternative models that have been proposed in the literature.

Response

Thank you for this comment. Most of the models mentioned in the literature are recent research models.

• Clearly state how the proposed research differs from or builds upon the existing models and approaches.

Response

Thank you for this comment. The differences in this model and approach are explained on page 16.

• Describe the process of analyzing and reconstructing the asperity profile and explain the rationale behind choosing the parabolic asperity model as the basis for the study.

Response

Thank you for this comment. The article has been modified and explained on page 5.

• If applicable, mention any software or computational tools used in the study.

Response

Thank you for this comment. The model curves were simulated and fitted with Matlab software. solidworks 3D software was used to design and simulate the 3D model, and origin software was used to draw the 2D model.

• Compare the findings with previous models or studies, highlighting similarities, differences, and potential reasons for discrepancies.

Response

Thank you for this comment. It is revised and explained on page 15 of the article.

Author Response File: Author Response.docx

Reviewer 3 Report

This study appears to be an original work involving analysis, modeling, and experimental studies on the normal contact stiffness of rough surfaces in grinding. This study is interesting and could be considered after incorporating major revisions. Please find comments below:

In the abstract, the purpose of this study should be explained in one or two sentences.

The introduction is sufficient. But, the novelty and scope of the study should be explained in detail.

It is recommended that the experimental methodology/schematic diagram be given in the material method section.

Is there a particular reason for using 304 steel in the experiment?

Results should be supported scientifically.

Authors should review and improve their English writing to correct errors and issues. The authors should carefully review their work to ensure that all errors have been corrected.

Author Response

We thank the reviewers for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

• In the abstract, the purpose of this study should be explained in one or two sentences.

Response

Thank you for this comment. We have made revisions in Abstract .

• The introduction is sufficient. But, the novelty and scope of the study should be explained in detail.

Response

Thank you for this comment. We have made revisions in Introduction.

• It is recommended that the experimental methodology/schematic diagram be given in the material method section.

Response

Thank you for this comment. The experimental schematic diagram is drawn on page 13 of the paper.

• Is there a particular reason for using 304 steel in the experiment?

Response

Thank you for this comment. 304 steel is the most commonly used metal material, so the test used 304 steel.

• Results should be supported scientifically.

Response

Thank you for this comment. On page 16 of the paper, a comparative model analysis method is added to confirm the validity of the model.

Author Response File: Author Response.docx

Reviewer 4 Report

1) It is necessary to add a section on materials and methods. Since it is not clear from the text of the article what materials were used in the study. Describe in detail all the methods presented in this section.

2) The reference section needs to be slightly expanded to at least 25 positions.

3) It is not clear from the text in what software the 3D model in Fig. was obtained. 5, 6?

4) Formulas (1) and (2) have different fonts. Further in the text there is no numbering of formulas.

5) In paragraph 3, the authors provide a mathematical description between the contact load, stiffness and displacement variable. However, no analytical or numerical solutions are provided. It would be advisable to include below a table with parameters for solving these physical dependencies. The same applies to paragraph 3.3.

6) In the annotation section, it is necessary to indicate with what precision the processing of the connected parts was carried out, if we are talking about grinding.

7) In conclusion, there are no numerical research results (profile parameters and topography characteristics).

English needs minor improvement

Author Response

We thank the reviewers for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

• It is necessary to add a section on materials and methods. Since it is not clear from the text of the article what materials were used in the study. Describe in detail all the methods presented in this section.

Response

Thank you for this comment. Material properties (Young's modulus E1=E2=209Gpa, Poisson's ratio ν1=ν2=0.269, hardness H=1970Mpa) are introduced in the experimental section on page 12 of the paper.

• The reference section needs to be slightly expanded to at least 25 positions.

Response

Thank you for this comment. We have made revisions in Introduction.

• I It is not clear from the text in what software the 3D model in Fig. was obtained. 5, 6?

Response

Thank you for this comment. The 3D model is drawn with SOLIDWORKS 3D design software.

• Formulas (1) and (2) have different fonts. Further in the text there is no numbering of formulas.

Response

Thank you for this comment. Article formulas have been revised and numbered.

• In paragraph 3, the authors provide a mathematical description between the contact load, stiffness and displacement variable. However, no analytical or numerical solutions are provided. It would be advisable to include below a table with parameters for solving these physical dependencies. The same applies to paragraph 3.3.

Response

Thank you for this comment. For detailed explanation, please read the references I cited (Bai, Y.; An, Q.;  Suo, S.;  Wang, W.;  Jia,  X. An Analytical Model for the Normal Contact Stiffness of Mechanical Joint Surfaces Based on Parabolic Cylindrical  Asperities. Materials 2023, 16, doi:10.3390/ma16051883.)

• In the annotation section, it is necessary to indicate with what precision the processing of the connected parts was carried out, if we are talking about grinding.

Response

Thank you for this comment. It is indicated on page 12 of The paper that The roughness of the joint surface was Sa0.854μm, Sa1.173μm, Sa 1.391μm and Sa1.524μm, respectively.

• In conclusion, there are no numerical research results (profile parameters and topography characteristics).

Response

Thank you for this comment. The results of the numerical study are analyzed on page 5 of the article.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Dear Editor,

I have thoroughly reviewed the revised manuscript along with the authors' responses. The revisions made by the authors appear to address the concerns raised during the initial review adequately. However, I would like to suggest an enhancement to improve the clarity and accessibility of the materials and methods section. Specifically, I recommend the inclusion of a comprehensive flowchart detailing the key steps of the research process. Integrating this visual aid at the outset of the materials and methods section would likely enhance readers' comprehension of the research methodology.

Thank you for your attention to this matter.

Sincerely

Author Response

                         Response to Reviewer 1 Comments

We thank the reviewer for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

I have thoroughly reviewed the revised manuscript along with the authors' responses. The revisions made by the authors appear to address the concerns raised during the initial review adequately. However, I would like to suggest an enhancement to improve the clarity and accessibility of the materials and methods section. Specifically, I recommend the inclusion of a comprehensive flowchart detailing the key steps of the research process. Integrating this visual aid at the outset of the materials and methods section would likely enhance readers' comprehension of the research methodology.

Response

Thank you for this comment. Please check the attachment for the flow chart drawn on page 3 of the article.

Author Response File: Author Response.docx

Reviewer 3 Report

The revisions are appropriate, and the article can be accepted as is.

Author Response

                         Response to Reviewer 1 Comments

We thank the reviewer for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

The revisions are appropriate, and the article can be accepted as is.

Response

Thank you for this comment. Thank you for your careful revision of this article!

Reviewer 4 Report

I have read the responses to comments. The authors of the article responded to all comments and significantly improved the article. The article is recommended for publication.

Author Response

                          Response to Reviewer 4Comments

We thank the reviewer for his careful read and thoughtful comments on the previous manuscript. We have carefully taken his comments into consideration in preparing our revision, which has resulted in a paper that is clearer, more compelling, and broader. The following summarizes how we responded to the reviewer comments.

Comments:

I have read the responses to comments. The authors of the article responded to all comments and significantly improved the article. The article is recommended for publication.

Response

Thank you for this comment. Thank you for your careful revision of this article!

Author Response File: Author Response.docx