Dynamic Analysis and Parameter Optimization of the Cutting System for Castor Harvester Picking Devices
Yoshihisa Fujii
Iwao Uehara
Round 1
Reviewer 1 Report
Dear authors,
due two the following points, your paper was judged as "reject"
1. The detailed explanation on the principles, procedures and condition of the FEM is lacking, so that the results can not be evaluated.
2. Theoretical background should be revised, taking the changes in the force and material parameters in proceeding of cutting process into consideration.
3．The process of cutting is a kind of fracture process. This can note be explained only by the mechanical properties of the stalk.
Author Response
On behalf of my co-authors,we appreciate editor and reviewers very much for their positive and constructive comments and suggestions on our manuscript. We have studied reviewer’s comments carefully and the responds to the reviewer’s comments are as flowing:
- Response to comment: The detailed explanation on the principles, procedures and condition of the FEM is lacking, so that the results can not be evaluated.
Response: As seen from the references I quoted, the specific operations in the simulation software, such as the setting of material properties and the specific steps of material selection, are generally not detailed in the paper. However, I provided the parameters I set and the connection mode of FEM-SPH coupling simulation model in the paper. The simulation model has repeatability and can provide reference for stalk cutting. And the optimization results of the coupled simulation model are verified, which is also a self-evaluation of the calculation results.
- Response to comment: Theoretical background should be revised, taking the changes in the force and material parameters in proceeding of cutting process into consideration.
Response: In this paper, through the theoretical analysis of the contact and collision process between disc cutter and stalk, combined with the previous single factor field experiment. The main purpose is to select some test factors that have a significant influence on the maximum cutting force, such as feeding speed, disc cutter thickness, etc. Secondly, because the stalk as the agricultural materials is a kind of viscoelastic-plastic and anisotropic complexus. The relationship between cutting force and material parameters of stalk is not linear. It is necessary to measure the material characteristics under the different conditions (such as different water content, different thickness and different direction) of the stalk, so that the corresponding theoretical process analysis can be carried out. Therefore, the parameter changes of force and material parameters are not discussed in this theoretical analysis process. In the future study, I will conduct experiments and research on these material characteristic tests and mechanism analysis of cutting process. This paper still focuses on the analysis of the maximum cutting force by FEM-SPH coupling simulation model, the optimization of test parameters and the simulation model verification test.
- Response to comment: The process of cutting is a kind of fracture process. This can note be explained only by the mechanical properties of the stalk.
Response: We appreciate for reviewers’ warm work earnestly. I couldn’t agree any more, the process of cutting is a kind of fracture process. As mentioned above, castor stalk is not continuous material, the cutting force of castor stalk is dynamic change value, and the cutting action time is very short. With reference to relevant literature information, this paper tried to simulate the dynamic cutting process of castor stalk as much as possible through a simplified stalk model and obtain the optimized parameters combination range. This result may encourage other readers to consider using similar models and refer to the process parameters of disc cutter when designing cutting devices.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This is a unique and practical research paper that investigated the optimization of the cutting system from various angles, such as the thickness of the disk cutter, the angle of the blade, and the rotation speed of the disk cutter of the harvesting machine!
However, how about the sharpness of the blade itself? The sharpness of the blade is not mentioned in this paper, but some disc cutters have good blade sharpness and others have bad blade sharpness. It naturally controls the harvesting efficiency.
Please add the sharpness of the disk cutter blade by a coefficient, or some factors, if you can!
Author Response
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript; we appreciate editor and reviewers very much for their positive and constructive comments and suggestions on our manuscript. We have studied reviewer’s comments carefully and have made revision which marked in the paper. The main correction in the paper and the responds to the reviewer’s comments is as flowing:
Response to comment: how about the sharpness of the blade itself?
We gratefully appreciate for your valuable suggestion. The previous single-factor test results with different cutter disc parameters indicated that there are many factors affect the maximum cutting force. In this test, the cutter disc rotate speed, feeding speed, disc cutter thickness and edge angle, which have significant influence on the maximum cutting force, was selected as the test factor. Among them, the cutter disc thickness and edge angle have a direct linear relationship with the sharpness of the blade. We have referring to the related literature of the blade sharpness. The smaller the edge angle under the same cutter disc thickness conditions, the sharper the blade. The test method in this paper adopts the orthogonal rotation combination test, which analyzes the interaction of different test factors on the maximum cutting force. If the sharpness of the blade is added as a test factor, the analytical model will produce a significant error. Therefore, the sharpness of the blade was not added as a influencing factor for discussion in this test. But, I’ll studies and analysis the influence of the sharpness of the blade on the harvesting efficiency in the future study.
Author Response File: Author Response.docx
Reviewer 3 Report
Dear Authors, congratulations on the article. Below are some minor comments
Please complete the caption of Figure 7. What does (a) and (b) mean?
Section 4.2. Parameter optimization - can't start like this. Please enter a description.
The title of chapter 4. Discussion - introduces an error. The discussion suggests referring your own results to the results presented in the literature.
It is a pity that the authors did not attempt to demonstrate the presented results in practice. How the selection of parameters will affect fuel consumption, efficiency or durability of working units.
Best regards
Author Response
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript; we appreciate editor and reviewers very much for their positive and constructive comments and suggestions on our manuscript. We have studied reviewer’s comments carefully and have made revision which marked in the paper. The main corrections in the paper and the responds to the reviewer’s comments are as flowing:
- Response to comment: Please complete the caption of Figure 7.
Response: We gratefully appreciate for your valuable suggestion. We've added the description of what is contained in the panel of Figure 7. For details, please refer to section 4.1.
- Response to comment: Section 4.2. Parameter optimization - can't start like this. Please enter a description.
Response: Thank you for your valuable suggestion. We've added the description of constraint conditions. For details, please refer to section 4.2.
- Response to comment: The title of chapter 4. Discussion - introduces an error. The discussion suggests referring your own results to the results presented in the literature.
Response: We appreciate for reviewer’s warm work earnestly. We have rearranged chapters and renamed the sections. For details, please refer to chapter 3 and chapter 4.
- Response to comment: It is a pity that the authors did not attempt to demonstrate the presented results in practice. How the selection of parameters will affect fuel consumption, efficiency or durability of working units.
Response: We appreciate for reviewers’ warm work earnestly. I couldn’t agree any more, the selection of parameters will affect fuel consumption, efficiency or durability of working units. As this test focuses on verifying whether the simulation model is reasonable, the verification of equal evaluation index as efficiency or durability of working units were not carried out. But I’ll studies and analysis the influence of the optimal parameters on the fuel consumption and harvesting efficiency in the future study.
Author Response File: Author Response.docx
Reviewer 4 Report
Dear Authors,
Hereby I would like to present my review of your article:
In general, the topic is interesting and the results are presented clearly. However, there are several issues, that require improvement - but please be not discouraged by my comments:
1. There are definitely too many comas (",") and the in some places the sentences are too long and complex, in my opinion some readers may have difficulties with comprehension. Please break those sentences down or rearrange them, as shown in the example provided by me in the abstract.
2. The introduction is well-written in the matter of state-of-the-art and used methods, however I would like to see some examples of materials used in cutting disc fabrication. I believe, that the rotational speed and angle are really important factors, however in the agricultural business wear caused by the abrasive soil particles may also play a major role, which was not stated in the paper. It is rather a "nice to have" feature, than a "must have" one.
3. The equations' description, presented in "Materials and Methods" may be improved by separating the meaning of symbols with a new line for each one.
4. The readers may benefit from more clear arrangement of the headers, as stated in my comments.
5. The section 2.3 lacks one or two introductory sentences.
6. I was taught, that all of the references shall be placed in the introduction and that one should refrain from putting sources in other sections. I find this not as a mistake, however other reviewers might have different opinion.
7. Torque sensor has no description in chapter 2.4.1
8. The conclusions section provides your results in a clear way, however - from the practical point of view - your paper might benefit from providing additional information about the "acceptable ranges" of parameters. I am aware, that your experiment resulted in the singular, best set of parameters, yet the manufacturers may be unable to achieve those parameters so strictly in every circumstances. The surface response method should have given you reasonable range of parameters, that will elongate the operating lifetime of disc cutters. Also, please underline strongly the original finding of your research.
Again, I do like the organization of your research, the expertiment is well conducted and the resultant values seem reliable and proven with statistics, but I encourage you to enhance the legilibity and readability of some parts of the paper (tables, formulas etc.) and most importantly - to provide the reasonable range for real-life application
[side note - I believe that farmers and assembly workers may have no idea how to measure 29.2°]
Comments for author File: 
Comments.pdf
Author Response
On behalf of my co-authors, we thank you very much for giving us an opportunity to revise our manuscript; we appreciate editor and reviewers very much for their positive and constructive comments and suggestions on our manuscript. We have studied reviewer’s comments carefully and have made revision which marked in the paper. We have tried our best to revise our manuscript according to the comments.
- Response to comment: There are definitely too many comas (",") and the in some places the sentences are too long and complex.
Response: We gratefully appreciate for your valuable suggestion. The sentences are too long and complex has been rewritten.
- Response to comment: In the agricultural business wear caused by the abrasive soil particles may also play a major role, which was not stated in the paper.
Response: Thank you for your valuable suggestion. We've added some references in the ’introduction’ section to introduce the material of disc cutter. For details, please refer to section 1. Because the cutting part of castor stalk is located 15 cm above the ground, the disc cutter wear caused by soil particles is rare. And in our early field tests, there were really very few soil particles on the disc cutter. Therefore, the wear of soil particles is not taken into account in this paper.
- The equations' description, presented in "Materials and Methods" may be improved by separating the meaning of symbols with a new line for each one.
Response: We appreciate for reviewers’ warm work earnestly. According to the template, the equations need not be a new paragraph. Therefore, we haven't made changes to the equations' description.
- Response to comment: The readers may benefit from more clear arrangement of the headers.
Response: We gratefully appreciate for your valuable suggestion. Some headers have been checked and rewrite for easy understanding. And some marked details also have been corrected.
- Response to comment: The section 2.3 lacks one or two introductory sentences.
Response: Thank you for your valuable suggestion. We've added the introductory sentences in the section 2.3. For details, please refer to section 2.3.
- Response to comment: all of the references shall be placed in the introduction and that one should refrain from putting sources in other sections.
Response: We appreciate for reviewers’ warm work earnestly. In this paper, I cited some material characteristic parameters and test methods, I hope that readers can quickly find these literature sources. Therefore, some references can be found in other sections in the paper. And I have kept these references for ease of reference.
- Response to comment: Torque sensor has no description in chapter 2.4.1.
Response: Thank you for your valuable suggestion. We've added the sentences for describe the torque sensor in the chapter 2.4.1.
- Response to comment: The surface response method should have given you reasonable range of parameters, that will elongate the operating lifetime of disc cutters. Also, please underline strongly the original finding of your research.
Response: Thank you for your valuable suggestion. We have given the reasonable range of optimal parameters instead of in the singular, best set of parameters.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear authors,
I have investigated your revised paper, and concluded as "reject".
The revised version was not properly corrected, reflecting the comments last time.
