Simulation, Fabrication and Testing of UAV Composite Landing Gear

Round 1

Reviewer 1 Report

Authors presented a study of flexural properties of many materials used to produce a landing gear part for unmanned aircrafts. The study comprises mold and additive manufacturing fabrication and properties were both simulated and experimentally determined and discussed. The work is well driven and interesting. I let my comments in the attached file to help improve clearness of the work.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

The mechanical properties of the materials used by FFF have to be mentioned in a table.

Why authors did not inspect the materials based on ASTM or ISO to decide the suitability of the material for producing the part with the same geometry? Replacement of any material with another one will have an impact on the design, in this case, will be the thickness, as replacing the current CFRP with wood, it works but the thickness will be bigger, as the equivalent section will be calculated based on the stiffness one time, and the deformation second time, and then taking one of them based on the design.

The standard deviation of the experiment works is supposed to be shown on the diagram.

Boundary conditions are not shown? why used fixed for both sides?

The tested part must be shown in a diagram from the main structure in Figure 1.

If the part is fixed on the plane at segment "B", bonded or fixed, means the plane load will affect the curved sides, as an cantilever, why did not consider this situation in the testing? 

The overall stiffness of the tested piece must be estimated since no standard was followed in the testing.

There is no single equation used in the paper?  must be used

The colors used in Fig 5, on the left, are not suitable, especially using Blue color, making it confusing between the material.

How many samples for each material were tested? 

For Fig.7, which stress do you mean? you need to show how did you calculate the stress experimentally with the necessary equations.

Authors need to use the energy method to estimate the overall deflection of the tested parts, since the part is a combined shape, and then compare it with the FEA and experimental work.

 

 

 

 

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

On lines 129–132, the authors write about the good properties of materials. It would be nice to give the numerical values ​​of these properties with reference to studies.

 

In Figure 1b, the authors show schematically a part that is made from new material. It is worth giving a diagram of the forces acting on this part.

 

In the Methodology, the authors write about the addition of short glass fibers for reinforcement: it would be nice to provide photographs or parameters of these glass fibers.

 

For testing, the paper's authors use the scheme shown in Figure 3. In this scheme, the wheel attachment points are limited in movement in the horizontal direction. However, in reality, the wheels will have a friction force on the rolling plane, but there will be no restriction on moving to the sides in a horizontal direction. Distance D from Figure 1 may vary. In this case, to what extent will the test scheme correspond to reality? Please answer this question in the paper.

 

Add numerical data to the outputs with property values ​​and percentage changes in characteristics.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

2. Why authors did not inspect the materials based on ASTM or ISO to decide the suitability of the material for producing the part with the same geometry? Replacement of any material with another one will have an impact on the design, in this case, will be the thickness, as replacing the current CFRP with wood, it works but the thickness will be bigger, as the equivalent section will be calculated based on the stiffness one time, and the deformation second time, and then taking one of them based on the design.

The justification is not presented in the paper

4. Boundary conditions are not shown? why used fixed for both sides?

A diagram must be drawn to represent the BC

6. If the part is fixed on the plane at segment "B", bonded or fixed, means the plane load will affect the curved sides, as an cantilever, why did not consider this situation in the testing?

The justification and the assumption are not presented in the paper

7. The overall stiffness of the tested piece must be estimated since no standard was followed in the testing.

The linear stiffness of the object is applied force/displacement of the elastic zone, should be presented in a new diagram with explanation

11. For Fig.7, which stress do you mean? you need to show how did you calculate the stress experimentally with the necessary equations.

The justification and the assumption are not presented in the paper

12. Authors need to use the energy method to estimate the overall deflection of the tested parts, since the part is a combined shape, and then compare it with the FEA and experimental work. 

The justification and the assumption are not presented in the paper

 

 

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Thanks to the authors. The authors answered my questions. In my opinion the article can be published.

Author Response

Thank you very much for your comments.