Additive Manufacturing Gyroid Structures Used as Crash Energy Management
, Guillermo Reyes-Pozo 1, Josep Maria Puigoriol-Forcada 1, Francisco-José López-Valdés 2, Sriharsha Srinivas Sundarram 3 and Andres-Amador Garcia-Granada 1,*Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe article presents an analysis of the impact response of polymeric gyroid structures. The experimental plan is exhaustive, but the results are poorly commented on and require a more elaborated interpretation. The numerical model is scarcely described and the limitations are not discussed. Overall, the topic is of scientific interest, with experiments and numerical models providing added value to the work. However, a rigorous and scientific approach should be implemented in the analysis of the results to value the work.
Comments for author File: 
Comments.pdf
The English is sufficiently correct, however, the manuscript would benefit from spell-checking and some rewriting to improve fluency.
Author Response
We are grateful to reviewers for comments and useful suggestions that have helped us to improve our paper. As indicated in the responses that follow, we have taken all these comments and suggestions into account in the revised version of our manuscript.
For an animated gif of real impact and test visit the link https://meaagg.com/BIOCRASH/test_and_sim.gif
Please check the attached pdf file for detailed answer to your requests
Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
Introduction part
1) Introduction chapter, please try t oavoid formula in this chapter. All the mathematical information about TPMS must be reported in Method.
2) There some sentences inside the text that start with the reference: "(Chouhan and Bala Murali 2024) provide a comprehensive review of bioinspired gy-roid structures, focusing on manufacturing parameters and their impact on mechanical and thermal properties."
3) I think the introduction must be reorganized becasue there is a grat confusion with: compressive,impact and energy absorption.
Materials and methods
The image is not so good, maybe you can avoid the wireframe visualization.
What kind of gyroid? please define the formula in Materials and method.
What do the authors mean with Scaled to fit in size the cubes? What kind of scale? Which is the point of scale? They mean that for 50 mm the thickness is scaled with a factor of 50/20? Please explain this concept.
Sorry but the Table 1 has different cubes between Gyroid and Garcia-Granada. How do the authors conduct a comparison? Only 20 is the same.
Why did the authors choose this compression test? is there a normative?
Why is there a change of velocity?
It is not clear the type of impact test used and the explanation is very confused. For the equations please provide the equation out of text with a reference' number.
Also for the simulations, the impact one is not clear.
A suggestion could be to add images of these approaches. The instrument of the impact test and images about the pre-processing with boundary conditions of the simulations (compression and impact).
For example, the mangament of frictional with the compression test and the simulation with direction perpendicular to fabrication.
I suggest to define a nomenclature for the specimens inside Materials and method.
How did the authors pass between force-Displacement to Stress-Strain. Which is the area used?
All the graphs have a low quality.
There is something wrong with the Units in the graphs of the Figure 8a.
Also in the Graph 8b the ordinate can not be Energy. Maybe specific energy?
It is not clear how the authors defined these graphs.
I can not comment the 3.4 chapter because for me it is not clear how the authors performed impact tests both in experimental and numerical.
In order to improve the readibility the authors must specify for each aim of the paper the relative methodology. There is a confusion between methods and results.
The paper needs too much improvements and I think that it is not suitable in this condition to a publication.
Comments on the Quality of English Language
Thw quality of English is good.
Author Response
We are grateful to reviewers for comments and useful suggestions that have helped us to improve our paper. As indicated in the responses that follow, we have taken all these comments and suggestions into account in the revised version of our manuscript.
For an animated gif of real impact and test visit the link https://meaagg.com/BIOCRASH/test_and_sim.gif
Please check the attached pdf file for detailed answer to your requests
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe present paper addresses the subject of auxetic structures.
Considering the paper's subject, it is unclear what it is addressing.
1. The auxetic structure. The authors present the geometrical definition of the auxetic structure. Subsequently, they design a series of structures without any clear objectives or specifications. They point to previous work and reproduce the structures. This lack of clear objectives makes the contribution from this point of view minimal, highlighting the need for a more structured approach.
2. Structural performance. It is crucial to note that there is a substantial difference between compression and impact. The material model for impact analysis should consider the strain rate, but this is not adequately addressed, highlighting the need for a more comprehensive analysis.
3. Computational method. There is no information related to the convergence analysis. There is no information related to the meshing process. There is no information related to the interface models. There is no information related to the material model.
4. Material characterization. The authors mention different manufacturing directions. However, no results are related to the material's structural performance, and there is no plasticity model.
The paper is a mix of ideas. None of the items discussed are valid for a scientific journal, and the contribution is minimal.
Author Response
We are grateful to reviewers for comments and useful suggestions that have helped us to improve our paper. As indicated in the responses that follow, we have taken all these comments and suggestions into account in the revised version of our manuscript.
For an animated gif of real impact and test visit the link https://meaagg.com/BIOCRASH/test_and_sim.gif
Please check the attached pdf file for detailed answer to your requests
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsUnfortunately, my critical concerns about the applied methodology have not been addressed. Authors sustain that the procedure is meant to approximate the values, however there is no need to propose approximation equations to the only purpose of simplification. It is not acceptable for a scientific journal.
As highlighted in the previous revision, the research is not properly designed and the results are scarcely supported by data. There is a severe lack of criticism in the result analysis and many details are missing. Overall, it is not clear what is the contribution of the paper to the scientific community.
Although the topic could rise interest above the scientific community, its impact would be marginal. Unfortunately, the paper is not suitable for publication in its present form.
Comments on the Quality of English LanguageThe English could be improved, but it is sufficiently good to be understood.
Author Response
We are grateful to reviewers for comments and useful suggestions that have helped us to improve our paper. Please find attached our detailed answer to your comments.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Comments and Suggestions for AuthorsThe paper can be accepted for publication.
Author Response
We are grateful to reviewers for comments and useful suggestions that have helped us to improve our paper. Please find attached our detailed answer to your comments.
Author Response File: Author Response.docx
