Soil Particle Modeling and Parameter Calibration Based on Discrete Element Method

Round 1

Reviewer 1 Report

Manuscript concerns calibration of material parameters of soil particles applied for DEM modeling. Authors performed measurements o basic material parameters of soil particles and performed experimental study of the shear process of soil in the standard shear test. Applied contact model and ranges of particular material parameters, applied for DEM simulations, are appropriate. Applied procedure of calibration and validation were performed appropriately. Manuscript contains plenty of editorial mistakes briefly indicated in particular comments. The manuscript can be recommended for publication after minor revision following the following particular comments.

Particular comments:

1. Section "6.4. Validation of calibration parameters". Comparison of simulated and experimental values of the shear strength is fine, but simulated (Fig. 15) and experimental (Fig. 8) relationships of the shear process should be plotted on the same graph to enable precise evaluation of quality of fitting course of entire experimental curve of the shear process by the simulated line.

2. Lack of discussion and comparison of obtained results with findings of other researchers published already in scientific journals.

3. Lines 153-158, lines 172-179. Too much detailed description of procedures of standard tests.

4. Plenty of editorial mistakes:

Lines: 28, 36, 40, .... Lack of space between sentences.

Lines 45-47 and other places. Indication of reference from list of reference should follow the name of author: Chen at al. [9]. Lack of dot '.' after "al".

Table 1. Heading of the table. Lack of space between numbers and units, and between name of parameter and unit. The same remark of lack of space between number and unit concerns entire text of the manuscript.

Error in numbering of subsections: "6.3. Parameter calibration", "6.3. Validation of calibration parameters".

Author Response

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Reviewer 2 Report

The manuscript discusses the calibration of the DEM model for the interaction between soil particles, and then the accuracy of the calibration results is verified. This is an interesting application of particle simulation in agriculture. However, there are the following issues in the current version:

1.       The distribution of references needs to be further adjusted, for example, "the DEM is now widely used in the field of agricultural engineering [1 ~ 6]”.

2.       The level of soil moisture is an important parameter that gives different mechanical characteristics to the soil. How was this value taken? Is it the same for all the tests? If it is the typical or optimal value of the soil for sowing it is better to specify it.

3.       Why the particle diameter is chosen to be 1mm? Please explain it.

4.       In a lot of figures, in the axis label there is “name of the variable, measure unit”, please correct the space before the comma.

5.       The author should show the constructed discrete element model of the direct shear test and introduce the basic situation of that model.

6.       The abscissa of Fig. 15 should adopt displacement for better comparison with Fig. 8

 

7.       Moderate editing is needed.

Author Response

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