A Numerical Investigation of Delamination Response of CNT/Epoxy Film Interleaved Composite

Round 1

Reviewer 1 Report

The paper „A numerical investigation of delamination response of CNT/epoxy film interleaved composite” is well written, well structured and edited with care (small misspelling errors). The references are well selected, the figures are nice, and the manuscript includes numerical analyses as well as experimental results.

Nevertheless, the reviewer has some critical concerns regarding the following parts of article:

• formula 2.1 must have a reference to literature. The reviewer knows that it was taken from [23], but there it was derived based on the publication: “Russell, A.J. Factors Affecting the Interlaminar Fracture Energy of Graphite/Epoxy Laminates. In Proceeding of the ICCM-IV, Tokyo, Japan, 25–28 October 1982”. Hence, it would be appropriate to rely on the source of that dependence and be able to place it in the literature.
• Where so high K’i K’’ values come from, which, according to the experience of the reviewer, should be ten times less valuable (Figure.4, Table.4.).
• In the opinion of the reviewer, the description of numerical studies is too limited, making it difficult to replicate them by other researchers.
• Correct language error in line 26. It is “interface in between” and it should be “interface between”.
• Correct language error in line 44. It is “laminate with which Nylon 6,6” and it should be “ laminate in which Nylon 6,6”.
• Correct language error in line 85 where is no spaces between words and the parenthesis sign.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

Nanomodified materials are promising for use in engineering structures, but their properties require further study. The authors of the manuscript investigated the effect of the concentration of nanofibers as reinforcing elements on the strength of the laminated material. The simulation results are compared with experimental data for a beam with a span of 120 mm (lines 113, 151, 167, 194, 198). 

The research topic is relevant and interesting for many specialists in the field of composites.
Despite the large number of such works, each of them contains results that complement the overall picture and are therefore useful to specialists.
According to the reviewer, sections 3, 4 and 5 are written too succinctly. It is recommended to formulate the purpose of the work more clearly, as well as to detail the description of the methodology and the analysis of the results of modeling and experiments in order to strengthen the logical consistency of the sections of the manuscript.

Questions for the manuscript: 

1. Line 106:
   The origin of formula (2.1) should be explained.
2. Line 134-135:
   “Thus, Γ can be calculated as the area under the curve”.
   The text is too concise. More detailed explanations are needed; first of all it concerns the analysis of units of measurement.
3. Line 150-151: Figure 3.
   There is no color scale of the values shown in the figure.
4. Line 169-170:
   “The length of the cohesive zone is divided into ?_? (the length of front cohesive zone), and 1 − ?_? .”
   The length of the cohesive zone is equal 1, i. e. is dimensionless? Most likely, this is a typo.
5. Line 181: “Moroni et al.[24] “
   A point is missing. Formatting is required.
6. Lines 126-127:
   Figure 2 must be more detailed.
7. It is recommended to add a list of abbreviations and designations (for example, before the list of references).

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

1. Decipher the abbreviations KB, EN, CAS, CNT, CNT, CVD.
2. It is recommended to describe the manufacturing technology of samples in section 2 Experiments summary.
3. Explain how the data from Table 1 were obtained.
4. It is recommended to discuss how the obtained results can be used in engineering practice.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 4 Report

The paper “A numerical investigation of delamination response of CNT/epoxy film interleaved composite” needs the following revisions for further improvement:

1. The abstract needs improvement. The authors should focus more on why and what they have compared/done.
2. The paper requires English proofreading. Some of the sentences are too long.
3. In-text citations also have errors and need improvement. Some of the sentences also need citations of references.
4. The literature should be expanded with a state-of-the-art discussion, and then the novelty of the work should be presented.
5. The experimental study should be changed with materials and methods or some other appropriate headings
6. The results and discussion section needs justifications of results.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

If the abbreviation is used only once, then it is not recommended to use it (for example, DCB, PVDF, CAE and CFD). However, the manuscript contains references to articles in which these abbreviations are used as well-known, so this remark is not critical.

I would like more detailed explanations of the physical meaning of the values of t_N and t_T in in Figure 2b., although this is understandable to narrow specialists.

Author Response

The explanation for traction  was supplemented.

Reviewer 4 Report

The authors have improved the paper. However, the conclusions need improvement. Please, support the conclusions with the main findings/results.

Author Response

The conclusion was supplemented with explanations of the results and implications of this study.