Simulation of Track-Soft Soil Interactions Using a Discrete Element Method
Round 1
Reviewer 1 Report
This paper is interesting, but it can only be accepted with some changes.
I have listed some comments below
Introduction
No information on unmanned tracked vehicles. Where they are used. For what purposes? What is their construction like?
Material and Methods
Describe the symbols in the Figure 1. Which means Ri, Rj, α, δ….e.t.c.
Mean Absolute Percentage Error (MAPE) used to assess the accuracy of the simulation model should be reported in the methodology.
Results and discussion
There is a discussion of the results but no discussion.
Can the obtained results be compared with other models?
Is the Mean Absolute Percentage Error comparable with the other models?
Author Response
Point 1: (Introduction)
No information on unmanned tracked vehicles. Where they are used. For what purposes? What is their construction like?
Response 1: We are very thankful for the reviewer’s reminding. The research background of the manuscript is a kind of underwater tracked equipment, which is used for emergency rescue at the bottom of a river or reservoir. The research focus of the manuscript is the interaction between track and soft soil, so we only have a limited description of the unmanned tracked vehicle in the introduction section. The unmanned tracked vehicle in the manuscript is a verification platform to verified soft soil model, and the construction of unmanned tracked vehicle was shown in Figure 11.
Point 2: (Material and Methods)
- Describe the symbols in the Figure 1. Which means Ri, Rj, α, δ….e.t.c.
- Mean Absolute Percentage Error (MAPE) used to assess the accuracy of the simulation model should be reported in the methodology.
Response 2:
We are very thankful for the reviewer’s reminding.
- The symbols in the Figure 1 are explained in the following equations.
- We have reported the Mean Absolute Percentage Error (MAPE) in the Material and Methods section.
Point 3: (Results and discussion)
- There is a discussion of the results but no discussion.
- Can the obtained results be compared with other models?
- Is the Mean Absolute Percentage Error comparable with the other models?
Response 3:
We are very thankful for the reviewer’s reminding.
- The research focus of the manuscript is the DEM applied in the shear process between track segment and soft soil. The focus of the discussion is the comparative analysis of DEM simulation results and experimental results, not the comparison between different models.
Lines 376-386 We discussed the friction and cohesion characteristics of DEM scaled-up particles.
Lines 399-403、417-421 We discussed the removal effect of bulldozing resistance in DEM simulation.
Lines 438-446 We analyzed and discussed the errors of DEM simulation and corresponding test.
- In DEM simulation, not all contact models can be used to calculate viscous particles. The general DEM contact model ignores the effect of viscous force caused by liquid bridge, so it is not suitable for viscous particles. However, the JKR model in DEM simulation is a contact model that can be used to viscous particles modeling, which is modified the normal cohesion. Therefore, we think this result is inappropriate compared with other models.
3. The Mean Absolute Percentage Error is used to analyze the error between simulation results and experimental results, not the error between different models. We believe that other contact models in DEM are not suitable for soft soil modeling.
Reviewer 2 Report
Dear Authors,
I rate the manuscript highly. Minor remarks below.
1. There should be no formulas in the results. They should all be in the research methodology.
2. In the chapter the results should only be the results.
3. It describes in detail the results obtained; however, it lacks a discussion especially in relation to what is already available in the literature and on the market in terms of quantity-qualitative parameters.
Kind regards
Author Response
Point 1: There should be no formulas in the results. They should all be in the research methodology.
Response 1:
We are very thankful for the reviewer’s reminding. We have reported the Mean Absolute Percentage Error (MAPE) in the material and methods section. Make sure all formulas are in research methodology.
Point 2: In the chapter the results should only be the results.
Response 2:
We are very thankful for the reviewer’s reminding. According to the comments of the reviewer, we revised the result section. We only retained the results and moved the of the formula to the material and methods section.
Point 3: It describes in detail the results obtained; however, it lacks a discussion especially in relation to what is already available in the literature and on the market in terms of quantity-qualitative parameters.
Response 3:
We are very thankful for the reviewer’s reminding. The existing parameters we cited from the literature are the basic parameters of particles (i.e. wet density, Poisson ratio, shear modulus and particle size). These parameters have been applied in engineering field. However, the parameters of the contact model between particles cannot be measured directly (i.e. friction coefficient and surface energy). These parameters only be calibrated by DEM Simulation and corresponding experiments. Therefore, cohesion and friction properties between soft soil particles are the research focus of the manuscript. It should be noted that the DEM soft soil particles in the manuscript are applied with scaled-up mothod. The parameters of contact model cannot be generalized under the different scaled-up degree. Only under the same scaled-up degree, the reference of contact model parameters is valuable.
Reviewer 3 Report
In this paper, " Simulation of track–soft soil interaction using discrete element method" is to propose a soil modeling with discrete element method (DEM) to accurately simulate the interaction characteristics between soil particles and track. The topic may be of interest and useful for the readers. However, in terms of engineering point of view, the paper doesn’t seem to have a novelty because even unmanned tracked vehicles should run on soil that has sufficient engineering properties. The clay used in this study would be too soft to support the vehicles/tracks on the soil. Also, the English grammar/style of this paper including manuscript organization and quality of figures and tables should be substantially improved. Therefore, this manuscript would be rejected.
Author Response
Thank you for your comments. The authors‘ responses are attached below
Author Response File: 
Author Response.docx
Round 2
Reviewer 3 Report
There would be mere novelty still.
