Simulation and Analysis of the Working Process of Soil Covering and Compacting of Precision Seeding Units Based on the Coupling Model of DEM with MBD

Round 1

Reviewer 1 Report

The article is well-written. It has both experimental and simulation results. I have some minor comments for this article:

1. "Simulation analysis of the working process of soil covering and  2  
   compacting of precision seeding unit based on the coupling  3  
   model of DEM with MBD" -- you did experiments too?? please make more clear your title of the article.
2. Line 25-26: "The comparison between the experimental results and the simulated results shows that the trend is similar, and the two results are close." -- Please provide some quantitative results here (for example what is the error? some numbers not just saying "are close")
3. Line 27-28 "It also provides a new method for the design and  27  
   optimization of covering and compacting components of a precise seeding monomer. " -- Please make clear your conclusion. this sentence is too opaque.
4. Line 34-40 -- there is no reference here. please add some references.
5. Line 41-43 -- it can be better if "There is limited experimental research..., due to the complexity..."
6. Line 45 -- needs a reference.
7. Line 48 " And the field experiments were..." -- rewrite it.
8. Line 56 "by means of simulation. " -- rewrite it.
9. Line 56-58 "The flowing motion of the seeds and soils in the processing of covering and compacting was simulated by LS-DYNA software [8]." -- please introduce using FEM for the granular material first.
10. Line 56-66. Why FEM is not a solution for modeling granular material?? Please make it clear why you don't use FEM here. you can find the answer to this question here "https://doi.org/10.3390/ma14092174"
11. Line 67-75 -- the problem statement is not clear. What is the problem that this paper wants to solve?
12. Line 76-83: you need to address your sections here. For example, write "In Section 3, the 3D model of DEM ..., In Section 4, the results of simulation and experiment are compared" Something like that
13. Line 93-97: add a particle size distribution diagram of your soil sample. 
14. Line 126 "2.1.2. Soil compacting test"-- please provide a table in which all of your test information wrote in it.
15. Figure 3 -- needs to explain the subscription in the main caption of the figure. what is 1, b, c, ..??
16. 2.2. Simulation study -- how many particles did you use in DEM??
17. We need the know the size distribution of your simulation.
18. Why did you use the accumulated spherical model?? Please check "https://doi.org/10.3390/ma14195558" and find the answer and add it to your paper.
19. Figure 13 is not clear. make it bigger and add more information in the caption.
20. 19. What was your PC model? what was your run-time? what software did you use? please add them in the simulation part.
21. The conclusion needs to be specific. clear what was the error between simulation and experiment results by number.
22. Line 350-- add the future work.
23. References are not in the same shape. revise all of them. Please add the articles that I suggested in the previous questions.

Author Response

Dear Reviewer,

Thank you very much for your advice. We have revised the manuscript, and would like to re-submit it for your consideration. We have addressed the comments and the amendments are highlighted in red in the revised manuscript. Point by point responses to your comments are listed below this letter.  

We hope that the revised version of the manuscript is now acceptable for publication. We would like to express our sincere thanks to you for the constructive and positive comments.

 

 

I look forward to hearing from you soon.

 

With best wishes,

 

Yours sincerely,

 

Tianyue Xu

First author

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript is devoted to computer modelling of a seeder. Presented results may be useful by the readers interested in precision seeding. Unfortunately I'm not an expert in agriculture and related technologies, and therefore I can not comment on applicability and usefullness of the presented results for the industrial applications. Concerning simulation results, unfortunately, I'm not satisfied neither by description of the simulation techniques and models nor by the quality of the presented results. In my opinion, presented results (see e.g. figure 5, 17) do not allow to make reliable conclusions, because of high spread (dispersion) and low number of points (3 points per "line" only). Therefore I regret, but I cannot recommend publication of the present manuscript. However, the manuscript may contain some important applied results, which I cannot fully estimate for the reasons mentioned above.  

Author Response

Dear Reviewer,

Thank you very much for your advice. We have revised the manuscript, and would like to re-submit it for your consideration. We have addressed the comments and the amendments are highlighted in red in the revised manuscript. Point by point responses to your comments are listed below this letter.  

We hope that the revised version of the manuscript is now acceptable for publication. We would like to express our sincere thanks to you for the constructive and positive comments.

 

 

I look forward to hearing from you soon.

 

With best wishes,

 

Yours sincerely,

 

Tianyue Xu

First author

Author Response File: Author Response.pdf

Reviewer 3 Report

Lines 11-13: That sentence can be improved.
Material and Methods: all the redaction can be improved. It is not a list of definitions.
Lines 192-195: At least one dimension of the machine must be presented. You can add a scale in Fig. 9.
Lines 198 – 201: what is the stiffness of the springs?
Lines 199: What are the parameters of steels used? You need to specify.
Line 201: What are the compensation factor and spring index?
Line 212: Please specify the EDEM version used and the software provider.
Line 217: In DEM, contact parameters must be calibrated with experimental data. Several calibration procedures are presented in the literature. If you have experimental data, it is not clear why you use parameters of the literature.
Table 3: Please verify the formatting.
Lines 264-265: More information about the coupling method is needed, detailing the way in which the coupling is made.
Line 266: the simulation time is too low. Some of your results depend on the simulation time, and it seems like they are not in stationary conditions. Some graphics of the results over time can help to understand this. 
Line 271-272: What colors? Fig. 13 only has blue particles.
Line 287: That sentence is not adequately justified.
Lines 302-303: What colors? Fig 16 only has blue particles. 
Lines 311-312: How were the simulations consistent with those of the experiments? Please elaborate. In Fig 17a the simulations are inconsistent with the experimental data.
Line 287: That sentence is not adequately justified.
Figure 16: subfigures b), d) and f) do not present valuable information or are not specified. If they do not contribute to the work, remove the subfigures b, d, and f and keep only a, c, and e.

All the simulated results must be commented on in detail and the calculation procedure of these results must be presented.

Author Response

Dear Reviewer,

Thank you very much for your advice. We have revised the manuscript, and would like to re-submit it for your consideration. We have addressed the comments and the amendments are highlighted in red in the revised manuscript. Point by point responses to your comments are listed below this letter.  

We hope that the revised version of the manuscript is now acceptable for publication. We would like to express our sincere thanks to you for the constructive and positive comments.

 

 

I look forward to hearing from you soon.

 

With best wishes,

 

Yours sincerely,

 

Tianyue Xu

First author

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have improved the manuscript. I believe that it can be published in the present form.

Author Response

Dear Reviewer,

Thank you very much for your advice. We have revised the manuscript, and would like to re-submit it for your consideration. We have addressed the comments and the amendments are highlighted in purple/red in the revised manuscript. We would like to express our sincere thanks to you for the constructive and positive comments.

 

We hope that the revised version of the manuscript is now acceptable for publication. 

 

 

I look forward to hearing from you soon.

 

With best wishes,

 

Yours sincerely,

 

Tianyue Xu

First author

Author Response File: Author Response.pdf

Reviewer 3 Report

1. For a better understanding of Material and Methods you should improve the redaction.it is better to give cohesion to the paragraphs instead of simply listing the ideas. For example, in 2.1. Soil bin test, there are the definitions of Trail objective, Experimental location and Experimental instruments, without a connection between paragraphs. You can change to "The trail objective is ..." or something similar, taking care of the coherence and cohesion of your manuscript.

2. Line 213 or Fig. 9: A length or diameter of any part should be added to understand the size of the geometry.

3. It is necessary to specify the definition of compensation factor and spring index, or to cite an appropriate reference.

4. Line 234: you can add "calibration by means of angle of repose test.

5. Fig 9:  The constrain used can be presented in this figure. It is not clear where you apply the constrains.

6. Fig 13: The resolution of the figure can be improved increasing the ppp.

7. Line 294: The simulation time is too low. With 1.5 seconds of simulation you cannot expect to get steady state results. Also, because of the DEM-MBD coupling, you may need more time for the simulation.

8. Fig. 16: The Fig. 8 of the response letter can be added to a better understanding. Lines 334-336 are still mention the colors that it is not clear in Fig. 16.

Author Response

Dear Reviewer,

Thank you very much for your advice. We have revised the manuscript, and would like to re-submit it for your consideration. We have addressed the comments and the amendments are highlighted in purple/red in the revised manuscript. Point by point responses to your comments are listed below this letter. We would like to express our sincere thanks to you for the constructive and positive comments.

 

We hope that the revised version of the manuscript is now acceptable for publication. 

 

 

I look forward to hearing from you soon.

 

With best wishes,

 

Yours sincerely,

 

Tianyue Xu

First author

Author Response File: Author Response.pdf