Analytical and Numerical Solutions for Three-Dimensional Granular Collapses
, Yury Alkhimenkov 1,2,3,†, Michel Jaboyedoff 1,2,†and Yury Y. Podladchikov 1,2,3,†
Round 1
Reviewer 1 Report
The paper entitled "Analytical and numerical solutions for three-dimensional granular collapses", wrtten by E. Wyser and his collaboarators report a numerical and theoretical study of 3D granular colalpse.
The paper is clear and easy to read, the subject is interesting, but a few points are unclear to me and need to be clarified.
1. Where does eq. (5) come from? It would have something to do with the inertia of the collaps but this is not obvious at all to me. Yet, this equation is the key of the approach presented in the MS.
2. I do not understand which granular rheology is implemented in the numerical simulations. Is the young modulus reported (very low value by the way...) refers to the properties of the grains or to the propoerties of a effective continuum medium?
3. Conclusion should be less concise
Author Response
Please find our response in the attached file
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper proposes a combined approach between analytical, numerical, and experimental investigations of dry granular collapses considering a three-dimensional setting. The authors compare our analytical solution to (1) An experimental data collection using a newly designed apparatus and (2) the reference solution provided by Lajeunesse et al. A solution to unify the authors’ quasistatic hypothesis with the dynamic understanding of Lajeunesse et al. is then provided. The difference between numerical and experimental results shows good agreement, demonstrating that the author’s in-house solver is an effective tool for the three-dimensional modeling of granular collapse. One big problem in this paper is that the whole paper from the beginning (Abstract) uses a lot of first-person narratives, such as “we…, let us….” However, the first person should always be prohibited in scientific and technological writing. Overall, the reviewer recommends that the authors can clarify the following issues:
- Page 1, Line 7. Please explain what “MPM” means. The acronyms should always be defined the first time it is shown in the context, not later in Line 101 of Page 5.
- Page 2, Line 34. “θc = cst.” What is “cst” means? Constant?
- Page 2, Line 44. “The reference solution provided by [27]?” Please add the name before reference [27], or it will not be a complete sentence.
- Page 4, Line 85. What is the unit of n? 250 times or 250 degrees.
- Page 4, the line number is wrong. For the line after Line 77 (due to lack of line number in this line,) “and thus μ = 0.77.” Please explain how to calculate μ.
- Page 6, Line 117, “[37] showed.” This kind of statement is not allowed in the journal paper.
- Page 7, Line 163. Please add a reference for “ep2-3De v 1.0.”
- Page 7, Line 184. Please explain what RMSE (Root mean square error?) is.
- Page 8, Figure 8. This Figure’s resolution is not the same as other Figures. Please revise it.
- What is “[-]” mean in the x and y-labels of Figures 6, 7, 9, and 10?
Finally, some typos and minor grammar errors exist in this paper. Please check them carefully when the authors revise this paper.
Author Response
Please find our response in the attached file
Author Response File: Author Response.pdf
Reviewer 3 Report
The authors relate the rest angle of the particle to the initial aspect ratio of the cylinder by a theoretical approach + experimental method, which is verified by numerical simulations. The method is somewhat novel, but there are still some problems:
(1) In section 2, the authors describe the modeling process of MPM. It is suggested to add model illustrations or snapshots, which would be more intuitive.
(2) In Fig. 7, why the range of friction coefficient is chosen only from 0.5 to 0.9?
(3) In Figure 8, what is the definition of equivalent plastic strain in the bulk material?
(4) For the 3D model, how is the angle θ measured and defined?
(5) Is the theoretical formulation applicable to irregular particles?
Author Response
Please find our response in the attached file
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have addressed all my comments. To me, the MS can be published in its present form.
Author Response
Please find our response in the attached pdf file
Author Response File: Author Response.pdf
Reviewer 2 Report
Some grammar errors exist in this paper. Please refine them. Then the paper can be accepted. Thanks.
Author Response
Please find our response in the attached pdf file
Author Response File: Author Response.pdf
