Study on the Cell Magnification Equivalent Method in Out-of-Plane Compression Simulations of Aluminum Honeycomb

Round 1

Reviewer 1 Report

 

This study proposed an improved cell magnification equivalent method of honeycomb structures to improve the computational precision and efficiencyof the finite element model (FEM). A first-order decay exponential function (ExpDec1) is successfully established to predict cell magnification time. It is organized well and the logic looks nice. However, some questions should be addressed to further improve the quality of this paper:

1. Explain that why 16.7%~66.7% of the axial length is taken as the calculation interval in the definition of platform force, which will make the article easier to understand.

2. In Table 1, quantitative comparison, such as the specific values regarding deformation, may be better to be presented.

3. The formatting of the article can be improved. For example, the first letter of the keyword in the abstract should be lowercase.

4. The writing accuracy and scientificity of the manuscript need to be improved:

l  There is a unit symbol error in line 108: "g/cm3" should be "g/cm³".

l  References in line 237 are quoted in the wrong format.

l  When a proper noun appears for the first time in the full paper, it is marked with abbreviations. Abbreviations can be used later without re-emphasizing abbreviations. Please check the full text.

5. The FEM method used in the manu is not clearly described. For example, how is the drop weight load applied to the model? How the honeycomb model is meshed? It is recommended that the authors add a figure to show the FEM.

 

6. It should be noted that tenses should be proper and consistent throughout the manusrcipt, such as in lines 131-132, should it be in the past tense? And in line 95 of the article, the letter "F" should be italics.

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

1.      The abstract must be modified. It cannot appear “theoretically”. Is it or not?

2.      What kind of defects can appear in these materials?

3.      Poor discussion with open literature. The conclusions can be questionable. The results must be presented, discussed and justified.

4.      Only one impact? Impact until total rupture? Does the impact machine have “safety roads” to avoid repeating impacts?

5.      Line 207 – The four stages referred should be identified in the figure. I can only see three stages in Figure 5.

6.      Figure 5 - Is there the same behavior between the two figures? I don't think so!

7.      The discussion should be done in terms of percentages, to make it clearer for the authors.

8.      Line 282 – I Cannot see this.

9.      Line 314 - [2] – What does that mean?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

In the manuscript, the authors described compression behaviour of the honeycombs with large size and dense cells, and comprehensively analyses. The equivalent models with the same thickness to length ratio are established to analyse the compression performance of the honeycomb before and after cell magnification. Later, the study provides detailed insight to determine the cell magnification times. The manuscript is well organized and well-explained. However, a few areas might need minor description to improve comprehensibility:

1.  Author should add some more sentences in introduction part to describe the the efficacy of the proposed method.

2.  A description should add to describe the reason behind the stable fluctuation of curve with small cell wall (Figure 5b).

3.  Page 269: How the cell magnification relationship is also applicable to honeycombs of different size also need to explain Figure 7b? It is suggested to add one more explanation.

4.  Author should add main numerical results in conclusion part.

Author Response

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Author Response File: Author Response.docx

Reviewer 4 Report

The manuscript is mostly well structured, properly written, and try to resolves the original problem based on established methods. The topic of the work is interesting. I suggest that the manuscript be accepted for publication after the major revision and after authors take into account the comments and suggestions presented below.

1. What are the innovations of the research work? The objects, the research method, or new findings? In the reviewer’s opinion, none of them seems to be. Should be added in the introduction section with more clarity.
2. In the Introduction, more recent literature should be referenced.
3. The reason for selecting the sizes of specimens dimensions is not supported by any reference.
4. Only two sizes of specimens dimensions (cell wall length= 6 and 10 mm) are considered for the study which is not sufficient as different dimensions are used through the industry.
5. With regard to the overall configuration modelled via the finite element method and the details used in that model, there is insufficient detail presented in Section 1. There needs to be clear presentation of the boundary conditions utilized and the physical reasoning for their choice.
6. With regard to the details of the finite element meshing, there needs to be considerably more detail presented with full three-dimensional reference than can be discerned from Figure 1, and this needs to be clearly tied to the discussion presented within Section 1. Length scales for the various locations within the model need to be presented along with magnified views so that specifics details can be clearly understood. One particular example at present is the following sentence: “In the FE model, at least 3 elements are divided on the edge of the cell [23] .”. The details need to be clearly established. Beyond all this, the types of elements used throughout need to be clearly described and the reasons for the choices thereof established.
7. What is the basis of deciding the element size mesh for both projectile (moving rigid wall) and the honeycomb structure?
8. More details about the FE model and the analysis should be reported. Which results convergence was utilized?  Have the authors conducted any mesh convergence study?  Considering that the analysis is explicit, how was the time step determined?

9.    Page 3 line 110 ‘In this study, 0.20 is used as the friction factor of the metal material’ Author didn't discuss about the interaction between the projectile and separation cell walls. Its important part in the simulation, which can significantly changes the results. Why 0.2 of friction factor ? Justification is required.

10. The discussion for each figure is very minimal. Could you discuss more about relationships/relevance/applications/limitations, etc. in each of those figures.  
11. The discussion of the results and drawing of conclusions is rather superficial.
12. The results have been reported in the manuscript but justification is missing.
13. The figures 1 and 2 are unclear. The quality of figure should be much improved. Make it clearer.
14. The graphs 5 is unclear. It is suggested that the figures be plotted with scientific drawing tools.
15. References are too old or too limited. Please consider to expand the sections by looking for other examples of modelling of honeycomb sandwich panel under static and dynamic loads. More references should be considered the wide diffusion of this topic, including those numerical work, as an example:

·         https://doi.org/10.1007/s12008-017-0383-2

·         https://doi.org/10.1080/15376494.2021.1931991

·         https://doi.org/10.3390/ma15196982

16. The proposed 3 papers from point 15 should be inserted in References
17. Conclusion also requires some corrections it should be written in crisp language and all the finding should be reported.
18. Please improve the language used in the manuscript. Some words and sentence are not in form Academic Language.

 

The reviewer recommends a major revision to improve the overall value of this paper to the engineering community.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors responded positively to all my questions. Thanks!

Reviewer 4 Report

  Yuning Qiao et al have thoroughly revised the manuscript ID sustainability 2142027  entitled "Study on the cell magnification equivalent method in out-of-plane compression simulation of aluminium honeycomb" in accordance with the comments from the reviewers. The paper can be accepted now for publication in its current form in Journal of Sustainability.