Optimum Design of UAV Wing Skin Structure with a High Aspect Ratio Using Variable Laminate Stiffness
Round 1
Reviewer 1 Report (New Reviewer)
Excellent manuscript. Two suggestions:
1. English can be improved.
2. Authors may consider citing some more relevant and recent work done on CFRP stiffeners and also in NASTRAN to provide readers with a more comprehensive reference data base e.g. Parametric modeling, higher order FEA and experimental investigation of hat-stiffened composite panels
Author Response
The relevant matters are summarized and submitted.
Thanks.
Author Response File: 
Author Response.docx
Reviewer 2 Report (New Reviewer)
1. I think optimum design of UAV wing skin structure described in the introduction should elaborate about them advantages and disadvantages.
2. Why is you proposed a laminate parameter-based optimization strategy considering the stiffness characteristics of the two-dimensional elements used as design variables effective? The description is not clear.
3. Table 3，What is the basis for selecting parameter values?
4. I suggest that there should be a detailed analysis of the experimental results, for example: why the proposed method can produce better results?
Author Response
The relevant matters are summarized and submitted.
Thanks.
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
This paper presents an approach to optimize composite structures using Genetic Algorithms by allowing the thickness and fiber-orientation angle of the composite plies to be varied. There are a lot of concerns on this paper.
1- Although the title mentions “UAV wing skin structure” and “high aspect ratio”, the approach does not specific to these conditions. Does the approach work only for UAV wing skin with high aspect ratio? If not, then why the title mentions that. The reviewer believes that the title is not accurate enough.
2- The paper didn’t clarify the total number of minutes required to obtain the optimal solution using the proposed approach with genetic algorithms versus the time required with other approach such as mathematical optimization, artificial neural networks, etc. So, the main benefit is not clear to justify adopting the proposed approach.
3- The paper is not well-written at all. IT is full of typos, mistakes, and grammatical mistakes. It is very confusing to the readers. The readers of this respected journal deserve much better English that this. The construction of the sentences is wrong. The usage of the verbs is wrong. There is no way the reviewer can mention all mistakes here, because 70-80% of the paper needs significant changes. Here are very few examples:
a. Introduction: “In order to increase economic, efficiency, and practicality in aircraft design,”
b. Introduction: The composite material has excellent stiffness and significantly lower density compared to the weight generated compared to the metal material
c. Introduction: “Vasiliev et al. [3] proposed an actual method…” what do you mean by actual methods?
d. H. Han et al. [9] performed load analysis on the wings of the composite material SUNMIK aircraft under development. This paper was published in 2002, so the aircraft is no longer under development.
e. Section 2 title: “Theory for UAV’s Wing Structure Optimization” This should not be called Theory. It could be method or approach.
f. The word ply was written “fly” multiple times!
g. What is “stacked water” and “stacking water”? There is no water here!
h. You can’t start a paragraph or a sentence with “And”.
i. “Kriging” is not written correctly in figure 10.
j. What is “croaking”?
k. “reasonable A stiffness distribution was obtained.” Confusing.
l. …..
Reviewer 2 Report
The Engligh grammar must be significantly improved:
* For instance, in the abstract there is one sentence: "Optimum design result of composite wing was materialized by finite element model and reviewed by NASTRAN"; which I could not understand. Note that NASTRAN is a finite element solver.
* There are many typos and minor concordance errors that the authors should review: for example the authors wrote "fly" meaning "ply".
The main feedback is that a high-aspect ratio wing is usually aeroelastically constrained. Could you please discuss about this point? Note that many authors that you cite in the introduction dealt with aeroelastic phenomenon in the optimization, while designing or developing design methodologies for high-aspect ratio wings.
In the current manuscript, the authors constrained the optimization with the Tsai-Wu failure criterion and critical buckling. The critical buckling evaluated separately compression and shear. The authors should use a combined shear-compression critical buckling load, given that their interaction is nonlinear.
The authors showed the evolution of failure index, but could also have shown the evolution of the critical buckling load.
Reviewer 3 Report
This study conducted an optimum design of UAV wing skin structure with a high aspect ratio using variable laminate stiffness. An optimum strategy was proposed and verified. It contains valuable results. There are however following issues to be addressed before the manuscript can be considered for publication on the journal:
The introduction must be expanded, more references are suggested to be discussed. Such as: https://doi.org/10.1016/j.compstruct.2021.113605; https://doi.org/10.1016/j.compstruct.2022.115846. The effect of stacking sequence on the delamination, which is one of the most common failure types of composite laminate, is investigated and a delamination growth criterion is proposed. A numerical approach is established for the failure analysis of hat-stringer-stiffened aircraft composite panels.
In addition, please consider improving the introduction, provide more in-depth critical review about past studies similar to your work, highlight how does your current study brings new difference to the field.
If the optimum design method only applicable to symmetric stacking sequence? It is more interesting for the asymmetric one, where the elastic coupling exists and can be utilized for the wing aerodynamic performance design.
More details on the local and global finite element model should be given, including the mesh size.
There are some editorial and grammatical errors which affect the reading and understanding of the current research work and need to be further revised.
