Bird-Strike Analysis on Hybrid Composite Fan Blade: Blade-Level Validation
Round 1
Reviewer 1 Report
The paper studies the bird strike of composite fan blades, which is important to aerospace engineering. The materials used for the fan blade have Carbon fibers, Glass fibers , Epoxy resin and Titanium alloy, which is interesting. The numerical analysis is good. Some suggestions are given to improve the paper before publication:
1. Numerical models of the blade and bird need to be shown in detail, such the mesh, the element type, the contact, etc.
2. Interlaminar shear strain is used to consider the delamination /failure. It is better to consider the damage. It is not a must for this work, but can consider it in the future study.
3. Units in some of Figures are missing.
4. The language of the manuscript should be double checked, such as some of the symbols are not in italic.
5. The references are suggested to further expanded, such as the relevant literature: 10.3390/sym11101292
Author Response
Dear Sir
Please find attached file showing the author's reply to reviewers
Author Response File: 
Author Response.docx
Reviewer 2 Report
The work presented for review is an interesting study, the results of which can be applied to new blade solutions. Nevertheless, there are inaccuracies or understatements in work presented.
1. The analysis does not present a model divided by a grid, but only describes it. No information is given about the dimensions of the analysed blade, including approximate thickness and length and width. We can only infer the dimensions of the element from the bird model, the dimensions of which are provided - assuming that the scale of the elements is maintained in the model.
2. Information on the boundary conditions of the analysis is incomplete and imprecise, and it is difficult to determine what exactly was modelled. Information on the impact velocity is given, but there is no information on at least the other conditions of the analysis, whether the blade spinning speed, the resulting centrifugal forces, whether the pressure acting on the blade was taken into account,
3. What is shown in Figure 3. no legend is provided about the different colours.
4. The analysis does not provide information on the stresses that will be encountered, which appears to be an essential element when analysing the strength of a structure.
Author Response
Dear Sir
Please find attached the file showing author's reply to reviewer
Author Response File: Author Response.docx
Reviewer 3 Report
A simulation study was carried out for a hybrid composite fan blade to avoid delamination on the trailing edge region.
1) The results shown in the graphs can be discussed relating to the delamination damage
2) Section 5, the discussion needs to be comprehensive.
3) The fan blades are operated at high temperatures. Were the simulations carried out at elevated temperatures?
4) How the hybrid composites will behave under thermal expansion?
Author Response
Dear Sir
Please find attached the file showing author's reply to reviewer
Author Response File: Author Response.docx
Reviewer 4 Report
Type of the Paper (Article
One of the factors which significantly exerts a negative influence on flight safety is a collision of an aircraft with birds, commonly called bird strikes. The consequence of a bird sucked into the engine can be engine shutting down. Therefore the subject regarding numerical simulations of bird impact on the jet engine blade discussed in the article is important in the era of increasing air traffic density. Nowadays, numerical methods are widely exploited to model various components of aircraft in order to conduct simulated crashworthiness tests. Generally the paper is organized well. It contains all main parts of an original science paper.
Nonetheless, I have got several remarks regarding the paper.
Below the most important ones are specified.
• Chosen methods for the simulations are suitable and efficient, but their description is too general.
• A lack is the bird model validation. For example, the comparison of the values of pressure with Wilbeck’s results.
• A lack of comparison of Lagrange Mooney Rivlin bird model with SPH bird model, which is commonly used by investigators.
A lack of presentation of damage to the bird model process during the impact.
• Why has the bird mass 1.97 kg been chosen, while requirements of FAR 33.76 do not concern this bird mass.
• What flight phase was taken into account (take off, climbing, cruise, landing, etc). Why has the speed of 225 m/s been chosen?
• A lack is information regarding the impact parameters such as CONTROL, CONTACT, BOUNADRY, HOURGLASS, etc.
• In my opinion the energy balance is needed to show that total energy is almost constant (statement of the principle of energy conservation).
Authors should consider conducting studies in order to determine maximum velocity at which the blade will work correctly.
• Chapter 4 titled "Results and discussion" relates to the author's results exclusively and does not contain any discussion. In my opinion, these results should be compared with the results obtained by other researchers.
Author Response
Dear Sir
Please find attached the files showing the reply to reviewer and revised manuscript.
Thanks
Author Response File: Author Response.docx
Round 2
Reviewer 3 Report
The revisions have improved the manuscript.
Author Response
Dear Sir
Please find attached the files showing reply to reviewer and the revised manuscript.
Thanks
Author Response File: Author Response.docx
Reviewer 4 Report
Dear authors,
I accept the paper in present form
