Modelling and Simulation in High-Fidelity Crash Analysis of NGCTR-TD Composite Wing

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this manuscript, the authors focus on a standalone analysis of the wing, coupled with a lumped representation of the fuselage, and forms part of a broader effort that will include the most relevant vehicle systems, such as a complete fuselage model, in future crash simulations. Furthermore, this numerical activity has been benchmarked against experimental results obtained from a similar structure, specifically examining global acceleration at the wing's center of gravity. A significant correlation in terms of acceleration has been observed between our numerical model and the experimental test, highlighting the accuracy and reliability of the simulation in predicting the structural response during crash scenarios. The manuscript is recommended to be accepted after major revisions:

1.       Fig. 2 is marked as “Fig. 1” by mistake.

2.       Introduction: The authors firstly introduce the significance of analysis on the controlled failure of the wing during a crash to prevent fuselage collapse, and then the crucial role of modeling and simulation (M&S) in the design and development of aeronautical structures. However, the novelty of this paper is not impressive. Have other researchers carried out relevant work? What are their results and conclusions? Do they utilize modeling and simulation (M&S)?

3.       The deforming process of mechanical structures should be analyzed combined with their mechanical response curves, to help readers learn work mechanisms. The analysis of this work should be more thorough. (DOI10.1016/j.ijmecsci.2022.107893)

4.       The literature research can be further enhanced and reference number should be increased.

  Comments on the Quality of English Language

English language is fine in general. Several grammar mistakes can be further avoided by checking again carefully.

Author Response

Thank you for your detailed review of our manuscript. We appreciate your valuable feedback, which we have carefully considered and addressed in our revisions. In this letter, we provide responses to your comments and revisions, aiming to enhance the clarity and impact of our research. We are grateful for your contribution to improving our manuscript and hope that the revised version meets the standards for publication.

 

Comments and Suggestions for Authors

In this manuscript, the authors focus on a standalone analysis of the wing, coupled with a lumped representation of the fuselage, and forms part of a broader effort that will include the most relevant vehicle systems, such as a complete fuselage model, in future crash simulations. Furthermore, this numerical activity has been benchmarked against experimental results obtained from a similar structure, specifically examining global acceleration at the wing's center of gravity. A significant correlation in terms of acceleration has been observed between our numerical model and the experimental test, highlighting the accuracy and reliability of the simulation in predicting the structural response during crash scenarios. The manuscript is recommended to be accepted after major revisions:

1. Fig. 2 is marked as “Fig. 1” by mistake.

We have corrected this.

2. Introduction: The authors firstly introduce the significance of analysis on the controlled failure of the wing during a crash to prevent fuselage collapse, and then the crucial role of modeling and simulation (M&S) in the design and development of aeronautical structures. However, the novelty of this paper is not impressive. Have other researchers carried out relevant work? What are their results and conclusions? Do they utilize modeling and simulation (M&S)?

Thank you so much for this question. The answer has been also implemented in the manuscript:

In detail to this relevant topic, the design and effects’ evaluation of frangible section on the whole tiltrotor safety requirement is deemed crucial to qualify for flight with respect of Regulations. The use of high-fidelity modeling and simulation is novel for this type of topic for the following points:

• in terms of general approach. Others past experience was based on low fidelity modeling and static analysis (i.e. AW609). (Unfortunately, no public data available for reference);
• exploitation of high-fidelity modelling and simulation for viability of certification by analysis.

3. The deforming process of mechanical structures should be analyzed combined with their mechanical response curves, to help readers learn work mechanisms. The analysis of this work should be more thorough. (DOI10.1016/j.ijmecsci.2022.107893)

Thank you so much for this request. However, we are unable to find the reference paper. In addition, the analysis is referred to an assembled multi-material structure, for the aim of the study the frangible section local behavior is very well described by using displacement and damage contour.

4. The literature research can be further enhanced and reference number should be increased.

Thanks for the suggestion, we have provided as requested.

 

Comments on the Quality of English Language

English language is fine in general. Several grammar mistakes can be further avoided by checking again carefully.

Done

Reviewer 2 Report

Comments and Suggestions for Authors

The article “Modelling & Simulation in High-Fidelity Crash Analysis of 2 NGCTR-TD Composite Wing” is dedicated to simulation and validation of a drop test process.

I recommend revision with some improvements.

My recommendations:

 

1.       In title you can replace the “&” with “and”.

2.       Please write the author’s name according Aerospace template (Firstname Lastname ¹,....)

3.       Please rewrite the Abstract in a shorter form (max. 200 words), according to Aerospace template. Highlight the need and novelty of this study. Indicate the main conclusions and interpretations.

4.       Write the full description in Figure 1, not just the abbreviation. Put the image reference.

5.       Fill in reference 1 as indicated in the Aerospace template ("Site Title. Available online: URL (accessed on Month Day Year)".

6.       All figures and tables should be cited in the main text as Figure 1, Table 1, etc. Please check: (NGCTR-TD, Fig.1)- in line 46, „project's wing (fig.2) is uniquely” – in line 61, „MATL58 (table 1 and table 2), - line 154”, „shown in Fig. 4, were modeled” – in line 153, „shown in Fig. 5. – line 165”, „Al7050-T7451 (Table 4)” – line 174.....etc.

7.       Please complete the description in Figure 1. There are two pictures: a) CAD model of the wing, b) Device.....

8.       Reference 15 is in the theme of the text description?

9.       At the description of the finite element analysis, the quality criterion applied to the structural components must be clearly shown. For example, Part (element type) = number of elements. For shell elements is very important to specify the part thickness.

For a better understanding of the material assignment to the component parts of the assembly I recommend joining the parts photos with the tables of the material properties.

10.   I noticed that you described the reason for using the Hasin criterion, but please explain to 3.3 why the Hashin criterion was used to predict the damage and no other criterion was used, for example VonMises.

11.   In Figure 10 you have a Force-Displacement graph. Please specify the maximum displacement after drop test impact.

12.    The study was more complete if you had put the energy balance chart and description (Internal energy, Kinetic energy, Total energy and Hourglass energy).

13.   Please complete the Title of Figure 16. Try to make visible the text in the figure and a more consistent description.

14.   The recommendation in the future to use only one type of measurement unit used in the International System. If you use both systems, you must use them everywhere in the paper.

15.   In the Discussion section, it would be good if you could compare the results obtained from the simulation with the results obtained from a real impact made in the laboratory.

 

16.   Conclusions are few. Specify strong points of the study as well as the weaknesses (there is no physical validation).

Author Response

Thank you for your detailed review of our manuscript. We appreciate your valuable feedback, which we have carefully considered and addressed in our revisions. In this letter, we provide responses to your comments and revisions, aiming to enhance the clarity and impact of our research. We are grateful for your contribution to improving our manuscript and hope that the revised version meets the standards for publication.

Comments and Suggestions for Authors

The article “Modelling & Simulation in High-Fidelity Crash Analysis of 2 NGCTR-TD Composite Wing” is dedicated to simulation and validation of a drop test process.

I recommend revision with some improvements.

My recommendations:

1. In title you can replace the “&” with “and”.

Done

2. Please write the author’s name according Aerospace template (Firstname Lastname ¹,....)

Done

3. Please rewrite the Abstract in a shorter form (max. 200 words), according to Aerospace template. Highlight the need and novelty of this study. Indicate the main conclusions and interpretations.

Done

4. Write the full description in Figure 1, not just the abbreviation. Put the image reference.

Done

5. Fill in reference 1 as indicated in the Aerospace template ("Site Title. Available online: URL (accessed on Month Day Year)".

Done

6. All figures and tables should be cited in the main text as Figure 1, Table 1, etc. Please check: (NGCTR-TD, Fig.1)- in line 46, „project's wing (fig.2) is uniquely” – in line 61, „MATL58 (table 1 and table 2), - line 154”, „shown in Fig. 4, were modeled” – in line 153, „shown in Fig. 5. – line 165”, „Al7050-T7451 (Table 4)” – line 174.....etc.

Done

7. Please complete the description in Figure 1. There are two pictures: a) CAD model of the wing, b) Device.....

Done

8. Reference 15 is in the theme of the text description?

The reference was included by mistake, it has been removed.

9. At the description of the finite element analysis, the quality criterion applied to the structural components must be clearly shown. For example, Part (element type) = number of elements. For shell elements is very important to specify the part thickness. For a better understanding of the material assignment to the component parts of the assembly I recommend joining the parts photos with the tables of the material properties.

Thanks for the suggestion. We have included in the manuscript the distribution of thicknesses (Figure 6), and the number of elements. In addition, in the captions of Figures 3 and 4, the materials used have been indicated.

10. I noticed that you described the reason for using the Hasin criterion, but please explain to 3.3 why the Hashin criterion was used to predict the damage and no other criterion was used, for example VonMises.

Thank you so much for this question. The answer has been also implemented in the manuscript:

In this case study, Hashin's failure criterion was used to predict the initiation and progression of damage for composite parts. The reason for this choice is that it is a separate-mode criterion that, unlike others (such as Tsai-Hill or Tsai-Wu), allows us to discriminate whether the damage occurs at the fiber or matrix level, and to which stress it is coupled (tensile, compressive, shear), in order to better understand the composite structure behavior.

11. In Figure 10 you have a Force-Displacement graph. Please specify the maximum displacement after drop test impact.

In Figure 10, we have presented the compression behavior characteristic curve, which is used as input for the spring element in our study. The maximum displacement after the impact has been added in line 231.

12. The study was more complete if you had put the energy balance chart and description (Internal energy, Kinetic energy, Total energy and Hourglass energy).

Thank you for the suggestion. The energy balance has been implemented in Figure 12, and the following description has been added in the manuscript:

During the analysis, we observed a consistent energy balance: the initial kinetic energy is transformed into internal energy as the crash phenomenon progresses. As can be seen in the figure 12, it was chosen to terminate the analysis before the complete dissipation of kinetic energy. This decision was made because the focus of this work is the identification of the frangible section of the wing, and not the complete crash phenomenon, which will be studied by including the entire structure.

13. Please complete the Title of Figure 16. Try to make visible the text in the figure and a more consistent description.

Thank you for your comment, the Figure has been replaced and the following additional description has been added:

The time when the catastrophic failure of the lower panel begins was highlighted in the figure 18. It is remarkable that almost all the measured forces in the fuselage attachments exhibit significant peaks at that instant. This observation provides additional knowledge about the structural behavior during critical phases, enriching the understanding of failure dynamics.

14. The recommendation in the future to use only one type of measurement unit used in the International System. If you use both systems, you must use them everywhere in the paper.

Thank you for the suggestion.

15. In the Discussion section, it would be good if you could compare the results obtained from the simulation with the results obtained from a real impact made in the laboratory.

Currently the authors are authorized to discuss only acceleration global comparison, the rest of data are strictly confidential and covered by industrial clearance.

16. Conclusions are few. Specify strong points of the study as well as the weaknesses (there is no physical validation).

Thank you for the suggestion. The following explanation has been added in the Conclusion:

The strong points of this study are recognized in the stand alone analysis of the wing with a focus on the frangible section path and on the preliminary validation of the methodology with respect to similar physical test. Once a wing test article of NGCTR will be available, a full validation will be performed.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Most questions have been addressed. The recommended reference is listed as follows: 10.1016/j.ijmecsci.2022.107893

Flexible, efficient and adaptive modular impact-resistant metamaterials Comments on the Quality of English Language

Minor editing of English language required

Reviewer 2 Report

Comments and Suggestions for Authors

I agree with this version!