The Numerical Simulation of the Pressure Law and Control of the Hard Roof Face in the Far Field
Round 1
Reviewer 1 Report
The issues studied by the authors in this manuscript are common and have been studied extensively. At the same time, the research methods are also very ordinary. Before considering the acceptance of the manuscript, a major revision is required.
(1) The definition of far field in the manuscript is unclear. What distance is considered far field and does the selection of the research site (8106 working face of the Tashan coal mine) meet the far field conditions？
(2) What software is used for numerical simulation? How does finite element software achieve roof breaking (Fig 5f)? This worries me about the reliability of the simulation.
(3) Why is the difference in coal deformation between the front and back of the work face so large in numerical simulation? Aren't they using the same set of mechanical parameters (Fig5, Fig 12)? Please provide a detailed introduction.
(4) The quality of the images in the manuscript is too poor and unclear (Fig 8, Fig 12, Fig 13, et al.), and even the font size and format may differ in the same image (Fig 9).
(5) Equation 6 has not been edited correctly, please modify it.
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
1、The reviewer’s comments and suggestions:
The definition of far field in the manuscript is unclear. What distance is considered far field and does the selection of the research site (8106 working face of the Tashan coal mine) meet the far field conditions？
The authors’ answer:
The definition of far field is proposed by Gao Rui in the article "Research on the ore-pressure action Mechanism of the Fracture Instability of the hard Rock Formation in Far Field and the Control of Surface fracturing". It is defined as follows: under the mining conditions of extremely thick coal seam and above the basic top range, the morphology of the hard rock formation after breaking in this area is different from that of the near-field rock formation.
The distance is not defined by the far field, the pressure step between 30-65m will cause a large period of pressure, the working face to press strongly, 8106 working face to press the step distance of 51.6m, will cause a strong working face, to press in line with the definition of far field "large structure" failure and instability caused by the strong ore pressure of the working face.
2、The reviewer’s comments and suggestions:
What software is used for numerical simulation? How does finite element software achieve roof breaking (Fig 5f)? This worries me about the reliability of the simulation.
The authors’ answer:
In Abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached.
3、The reviewer’s comments and suggestions:
Why is the difference in coal deformation between the front and back of the work face so large in numerical simulation? Aren't they using the same set of mechanical parameters (Fig5, Fig 12)? Please provide a detailed introduction.
The authors’ answer:
In order to reflect the numerical simulation effect more clearly, the deformation amount is amplified, and the maximum stress criterion in the software is mainly used to judge the fracture of rock strata and judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point has been reached. The deformation and fracture of rock stratum are judged mainly by the values of stress and displacement.
4、The reviewer’s comments and suggestions:
The quality of the images in the manuscript is too poor and unclear (Fig 8, Fig 12, Fig 13, et al.), and even the font size and format may differ in the same image (Fig 9).
The authors’ answer:
Fig 8, 12 and 13 in the manuscript have been modified.
5、The reviewer’s comments and suggestions:
Equation 6 has not been edited correctly, please modify it.
The authors’ answer:
Equation 6 has been modified.
Many grammatical or typographical errors have been revised. All the lines and pages indicated above are in the revised manuscript.
Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors investigated the ground fracturing technology used to control mine pressure at the working face caused by hard top collapse, using finite element software. This research could fit with the scope of the journal, and it sound interesting for the scientific community. However, corrections and modifications should be carried out before publishing this work. Here are some comments that could help to improve the quality of this paper:
1. References
· The following references are not mentioned in the text: 3, and 11-16
· Reference 1 is repeated.
· Check the references and rewrite them according to the journal’s instructions.
2. Lines 61-63
· Check the language.
3. Lines 60-69
· Check the font.
4. Section 3
· As a background, you should add references.
· Figure 7
5. Add labels: A and B
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
1、The reviewer’s comments and suggestions:
References: he following references are not mentioned in the text: 3, and 11-16. Reference 1 is repeated. Check the references and rewrite them according to the journal’s instructions.
The authors’ answer:
3 and 11-16 citation questions have been revised.
2、The reviewer’s comments and suggestions:
Lines 61-63. Check the language.
The authors’ answer:
Lines 61-63 Language issues have been revised.
3、The reviewer’s comments and suggestions:
Lines 60-69. Check the font.
The authors’ answer:
The fonts for Lines 60-69 have been modified.
4、The reviewer’s comments and suggestions:
Section 3: As a background, you should add references. Figure 7
The authors’ answer:
The paper has been revised.
5、The reviewer’s comments and suggestions:
Add labels: A and B
The authors’ answer:
The paper has been revised.
Many grammatical or typographical errors have been revised.
Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper may be accepted after minor changes.
Comments for author File: Comments.pdf
The paper may be accepted after minor changes.
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
The authors’ answer:
（1）Formatting questions have been revised in the paper.
（2）Writing questions have been revised in the paper.
（3）Content issues have been revised in the paper.
Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: Author Response.pdf
Reviewer 4 Report
In this paper, the numerical calculation model of coal rock excavation and hydraulic fracturing coupling is established by using finite element software and its whole embedded cohesive element method, fluid-structure coupling theory and fracture mechanics theory. The results show that the initial hard roof pressure before fracturing is about 52 m, and the error rate of the initial pressure step is 0.07 % compared with the actual measurement results, which verifies the accuracy of the simulation. When the prefabricated crack spacing is 16 m, the initial pressure step after hard roof fracturing is reduced from 52 m to 24 m, and the vertical stress peak of coal seam working face is reduced by 40.59 %. It effectively reduces the mine pressure of working face caused by roof cross falling, which is more conducive to safe mining. This paper has done a lot of work, but there are still the following deficiencies :
1. Figure 1 and Figure 2 on page 2, line 57 and line 58 of the paper are not mentioned in the introduction. It is not known which point they are expressing. It is recommended to carefully review and modify them.
2. The formula ( 2 ) on page 3, line 87 of the paper suggests that the physical quantities should be explained .
3. On page 6 of the paper, line 181-184 of the description at a distance of 56 m from the opening and the cutting eye does not match the figure 6 of line 163, and it is recommended to carefully review and modify.
4. On page 9, it is recommended that Figure 10 on line 251, like Figure 4 on page 5, introduce the basic parameters of the model before modeling.
5. On the 10 th page of the paper, line 252-256 line description Figure 11 ' Fracture spacings of 16 m, 20 m, and 24 m were selected for the prefabricated 253 hydraulic fractures ', but it is difficult to see the described crack spacing in Figure 11 of line 261. It is recommended to modify the picture and add annotations to the picture.
6. The references cited in the article are relatively old, and it is recommended to add research in recent years to highlight the timeliness of the article.
Minor editing of English language required
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
1、The reviewer’s comments and suggestions:
Figure 1 and Figure 2 on page 2, line 57 and line 58 of the paper are not mentioned in the introduction. It is not known which point they are expressing. It is recommended to carefully review and modify them.
The authors’ answer:
All suggestions have been revised. Hard roofs near coal seams are typically addressed by water injection fracturing and deep hole blasting techniques,as shown in Figure 1.
They also controlled strong mine pressure emergence at the working face using pre-fracturing in the near area downhole and fracturing in the far field on the surface,as shown in Figure 2.
2、The reviewer’s comments and suggestions:
The formula ( 2 ) on page 3, line 87 of the paper suggests that the physical quantities should be explained .
The authors’ answer:
All suggestions have been revised.
3、The reviewer’s comments and suggestions:
On page 6 of the paper, line 181-184 of the description at a distance of 56 m from the opening and the cutting eye does not match the figure 6 of line 163, and it is recommended to carefully review and modify.
The authors’ answer:
All suggestions have been revised.
4、The reviewer’s comments and suggestions:
On page 9, it is recommended that Figure 10 on line 251, like Figure 4 on page 5, introduce the basic parameters of the model before modeling.
The authors’ answer:
All suggestions have been revised.
The other boundaries and loads are the same as the basic top initial pressure model in Chapter 3; (2) The Property module of the basic top increases the flow parameters of the fracturing fluid, including permeability, pore ratio, fracturing fluid viscosity, permeability coefficient, and the damage criterion remains unchanged; (3) Add the oil analysis step in the Step module, and set the injection duration, geometric nonlinear parameters, incremental steps and the maximum pore pressure change value of each load step. This analysis step is the simulation of Fracking injection stage. (4) During the pump shutdown stage, displacement constraints are applied to the flow velocity at the initial damage location to simulate the support effect of the proppant on the crack; (5) Carry out coal seam excavation and removal steps; Basic top elastic modulus-5.25 GPa, Poisson's ratio-0.24, tensile strength-9.36MPa, permeability coefficient-1e-7m/s, fracturing fluid viscosity-1e-14m Pa.S, peak displacement-0.02 m2/s pore pressure-20MPa.
5、The reviewer’s comments and suggestions:
On the 10 the page of the paper, line 252-256 line description Figure 11 ' Fracture spacings of 16 m, 20 m, and 24 m were selected for the prefabricated 253 hydraulic fractures ', but it is difficult to see the described crack spacing in Figure 11 of line 261. It is recommended to modify the picture and add annotations to the picture.
The authors’ answer:
All suggestions have been revised.
6、The reviewer’s comments and suggestions:
The references cited in the article are relatively old, and it is recommended to add research in recent years to highlight the timeliness of the article.
The authors’ answer:
All suggestions have been revised.
Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: Author Response.pdf
Reviewer 5 Report
The article is written in such a way that it is difficult to evaluate the results. The authors poorly described very important things:
1. How is the crack formation criterion introduced into the finite element method?
2. How do we see the collapse of the roof from the simulation results? In fact, the authors only analyze vertical stresses!
3. Perhaps the authors tried to describe the constitutive model, but it is difficult to understand the idea, since they do not provide links to the relevant articles, or even an explanation of most of the designations.
4. Authors call the same things by different terms. This further complicates the analysis of the results.
1.Line 60 why ore? And what does it mean "old top pressure?"
2.Line 60-62 - Not understandable
3.the meaning of Figure 3 is not clear
4.Line 86-87 Not understandable!
5.Formula 1 : - describe all symbols
6.Formula 2: what is “boundary of the force”, boundary of the displacement force? Describe all symbols!
7.Formula 3: What is J ?
8.Formula 6: statement pw -pw =0 should be explained
9.Line 11-113 different terms are used: “Immediate roof” then “direct top” For what?
10. Line 121-122 tautology!!
11. Line 112 what is OLD bottom?
12. Formula 7 : Change the symbols!!!
11. Line 118 Where is the top plate in the fig.4? Where are properties of this plate in the table 1?
12 Line 151 How can we see that it is the stress distribution that prevents collapse? Line I do not see any crack when the working face is advanced to 40 m
13 How can we see the appearance of cracks? What crack formation criterion is int roduced into the algorithm of the finite element method?
14 Line 191 What shows that the collapse occurs? the authors discuss only vertical stresses, but they do not indicate collapse
15 Table 2 What means “First time to press the step distance”. Why it is the same (56m) for all locations?
16 In what way “Initial incoming dynamic load factor” was obtained?
17 What is “brace support strength”? The same as strength of support according (8) or not?
18 formula 8. Give a link to the article or explain how this formula is derived
brace support strength
19 Line 213 - Looks like the figure 11 and 9 numbers are mixed up
20 Line 233-235 The phrase is incomprehensible, some definitions repeat each other, losing their meaning Show tne spacin range in fig 10!
21 Line 265 describe the designations!
22 Line 267 There are no boundaries and loads in section 3
23 Line 312 How can we see that the roof breaks? We see only stresses!!!! What is the criterion of roof collapse?
Comments for author File: Comments.pdf
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
1、The reviewer’s comments and suggestions:
How is the crack formation criterion introduced into the finite element method?
The authors’ answer:
The main idea of ABAQUS calculation of crack growth is to define a bonding main surface and bonding slave surface, and define the node set on the bonding slave surface, so that the main surface and bonding slave surface are bonded together through these nodes, and then specify the bonding contact properties and fracture criteria. Under load or displacement loading, when the criterion critical value is reached, the node breaks away from the main surface. It can only be used for two-dimensional crack propagation. In abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached.
2、The reviewer’s comments and suggestions:
How do we see the collapse of the roof from the simulation results? In fact, the authors only analyze vertical stresses!
The authors’ answer:
The main idea of ABAQUS calculation of crack growth is to define a bonding main surface and bonding slave surface, and define a set of nodes on the bonding slave surface, so that the main surface and bonding slave surface are bonded together through these nodes, and then specify the bonding contact properties and fracture criteria. Under load or displacement loading, when the criterion critical value is reached, the node breaks away from the main surface. It can only be used for two-dimensional crack propagation. In abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point is reached, and when the damage point is reached, the rock fracture is indicated.
3、The reviewer’s comments and suggestions:
Perhaps the authors tried to describe the constitutive model, but it is difficult to understand the idea, since they do not provide links to the relevant articles, or even an explanation of most of the designations.
The authors’ answer:
All suggestions have been revised.
4、The reviewer’s comments and suggestions:
Authors call the same things by different terms. This further complicates the analysis of the results.
(1) Line 60 why ore? And what does it mean "old top pressure?"
(2) Line 60-62 Not understandable
(3) the meaning of Figure 3 is not clear
(4) Line 86-87 Not understandable!
The authors’ answer:
Articles (1) and (2) have been corrected to indicate that the definition is reflected in the literature.
(3) Principle of effective stress This is an important principle that distinguishes soil mechanics from other mechanics. Soil is a three-phase system, and for saturated soil, it is a two-phase system. After the action of external load, the stress in the soil is shared by the soil skeleton and the water and air in the soil, but only the effective stress transmitted through the soil particles can make the soil deform and have shear strength. However, the pore pressure transmitted by water and air in the pores does not contribute to the strength and deformation of the soil.
(4) Simplified model: when the non-humid fluid can flow freely in the rock, it is assumed that the pressure of the non-humid fluid in the model does not change with the change of time. Compared with the wet fluid, the pressure is very small, and the influence of the average compressive stress of the non-humid fluid on the deformation of the rock medium can be ignored. The direct top is one or several layers of rock strata with similar properties located above the coal seam. Generally composed of shale, sand shale or silty rock, it has a certain stability and is easy to collapse with the fall of the working face. The basic top is a thick hard rock layer located above the direct top (some directly above the coal seam), whose collapse directly affects the stope pressure, usually composed of sandstone, limestone and sand rock.
5、The reviewer’s comments and suggestions:
Formula 1: - describe all symbols
The authors’ answer:
6、The reviewer’s comments and suggestions:
Formula2: what is “boundary of the force”, boundary of the displacement force? Describe all symbols!
The authors’ answer:
The boundary of force and the boundary of displacement are the limiting boundary conditions chosen in the calculation.
7、The reviewer’s comments and suggestions:
Formula 3: What is J ?
The authors’ answer:
J is the moment of inertia.
8、The reviewer’s comments and suggestions:
Formula 6: statement pw -pw =0 should be explained
The authors’ answer:
The void pressure on the boundary conditions is approximately equal to the void fluid pressure.
9、The reviewer’s comments and suggestions:
Line 11-113 different terms are used: “Immediate roof” then “direct top” For what?
The authors’ answer:
This simulation adopts Abaqus numerical simulation software, based on the actual geological mining conditions of Tashan 8106 working face and combined with the physical parameters of coal and rock measured at 8106 working face, a plane strain model of 59m×300m is established. The stratum buried depth is 417 meters, the seam thickness is 15m, the direct top thickness is 13m, and the basic top thickness is 15m.
10、The reviewer’s comments and suggestions:
Line 121-122 tautology!!
The authors’ answer:
All suggestions have been revised.
11、The reviewer’s comments and suggestions:
Line 112 what is OLD bottom?
The authors’ answer:
The old top is commonly known as the basic top, referring to the basic top, the basic top is located above the direct top (some directly above the coal seam) of the thick hard rock, its collapse directly affects the stope pressure, usually by sandstone, limestone and sand and other rock formation.
12、The reviewer’s comments and suggestions:
Formula 7: Change the symbols!!!
The authors’ answer:
All suggestions have been revised.
13、The reviewer’s comments and suggestions:
Line 118 Where is the top plate in the fig.4? Where are properties of this plate in the table 1?
The authors’ answer:
From the top down, the first layer is the basic roof, and the second layer is the direct roof. The direct roof is a layer or several layers of rock with similar properties located above the coal seam. It is generally composed of shale, sand shale or silty rock. It has certain stability and is easy to collapse with the fall of the working face. The basic top is a thick hard rock layer located above the direct top (some directly above the coal seam), whose collapse directly affects the stope pressure, usually composed of sandstone, limestone and sand rock.
14、The reviewer’s comments and suggestions:
Line 151 How can we see that it is the stress distribution that prevents collapse? Line I do not see any crack when the working face is advanced to 40 m.
The authors’ answer:
In Abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached. In order to reflect the numerical simulation effect more clearly, the deformation amount is amplified, and the maximum stress criterion in the software is mainly used to judge the fracture of rock strata and judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point has been reached. The deformation and fracture of rock stratum are judged mainly by the values of stress and displacement.
15、The reviewer’s comments and suggestions:
How can we see the appearance of cracks? What crack formation criterion is int roduced into the algorithm of the finite element method?
The authors’ answer:
In Abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached. In order to reflect the numerical simulation effect more clearly, the deformation amount is amplified, and the maximum stress criterion in the software is mainly used to judge the fracture of rock strata and judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point has been reached. The deformation and fracture of rock stratum are judged mainly by the values of stress and displacement.
16、The reviewer’s comments and suggestions:
Line 191 What shows that the collapse occurs? the authors discuss only vertical stresses, but they do not indicate collapse.
The authors’ answer:
In Abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached. In order to reflect the numerical simulation effect more clearly, the deformation amount is amplified, and the maximum stress criterion in the software is mainly used to judge the fracture of rock strata and judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point has been reached. The deformation and fracture of rock stratum are judged mainly by the values of stress and displacement.
17、The reviewer’s comments and suggestions:
Table 2 What means “First time to press the step distance”. Why it is the same (51.6m) for all locations?
The authors’ answer:
The appearance of ore pressure caused by the primary fracture of the basic roof in the coal face is called the primary pressure. Because the rock layer is thick and hard, the basic roof can be located in a large area, but the ore pressure is strong or extremely strong when collapsing. From the opening eye to the basic top first pressure, the distance from the top cutting line of the working face is called the first pressure step. It is the main index to reflect the stability of the basic top strata.
51.6m refers to the position of the cutting eye, and the cutting eye refers to the driving along the starting mining line of the coal face.
18、The reviewer’s comments and suggestions:
In what way “Initial incoming dynamic load factor” was obtained?
The authors’ answer:
Initial condition parameters entered in the abaqus software.
19、The reviewer’s comments and suggestions:
What is “brace support strength”? The same as strength of support according (8) or not?
The authors’ answer:
Hydraulic support is a structure used to control the mining pressure in the coal face. The mining face pressure acts on the hydraulic support in the form of external load. The hydraulic support is the same as (8).
20、The reviewer’s comments and suggestions:
Formula 8. Give a link to the article or explain how this formula is derived brace support strength.
The authors’ answer:
21、The reviewer’s comments and suggestions:
Line 213 - Looks like the figure 11 and 9 numbers are mixed up
The authors’ answer:
All suggestions have been revised.
22、The reviewer’s comments and suggestions:
Line 233-235 The phrase is incomprehensible, some definitions repeat each other, losing their meaning Show tne spacin range in fig 10!
The authors’ answer:
The comments have been revised. According to the research in the previous section, the reasonable period of pressing step is between 13-24m, and the crack spacing is 16m.
23、The reviewer’s comments and suggestions:
Line 265 describe the designations!
The authors’ answer:
24、The reviewer’s comments and suggestions:
Line 267 There are no boundaries and loads in section 3
The authors’ answer:
The boundaries and loads are the same as those shown in Fig 4.
25、The reviewer’s comments and suggestions:
Line 312 How can we see that the roof breaks? We see only stresses!!!! What is the criterion of roof collapse?
The authors’ answer:
In Abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached. In order to reflect the numerical simulation effect more clearly, the deformation amount is amplified, and the maximum stress criterion in the software is mainly used to judge the fracture of rock strata and judge the start of damage. When the ratio of stress to the critical value in any direction is 1, it means that the initial damage point has been reached. The deformation and fracture of rock stratum are judged mainly by the values of stress and displacement. The boundaries and loads are the same as those shown in Fig 4.
Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
good.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 2 Report
The authors have addressed most of my concerns.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 5 Report
1.The authors made a minimal revision. I thank the authors for their responses to my comments. But these answers are important not only for the reviewer, but also for the reader. I did not see significant changes in the text of the article.
2.The authors should explain to the readers (not the reviewer) what is the criterion for the occurrence of a crack. What is the critical stress value that must be reached for a crack occuring? Nowhere in the text of the article is said about these critical values.
3.Some phrases in the text of the article, which I considered stylistically incorrect, were not revised by the authors.
4. Links for formula 8 should be given in the article (not for the reviewer)
5. Line 129 . Explain for the readers what is hard top plain
Comments for author File: Comments.pdf
Author Response
Dear reviewer,
I am very grateful to your comments for the manuscript. According with your advice, we amended the relevant part in manuscript. Some of your questions were answered below.
1、The reviewer’s comments and suggestions:
The authors made a minimal revision. I thank the authors for their responses to my comments. But these answers are important not only for the reviewer, but also for the reader. I did not see significant changes in the text of the article.
The authors’ answer:
Thank you very much for your comments, I will revise the content of the article again, and thank you again for your comments.
2、The reviewer’s comments and suggestions:
The authors should explain to the readers (not the reviewer) what is the criterion for the occurrence of a crack. What is the critical stress value that must be reached for a crack occurring? Nowhere in the text of the article is said about these critical values.
The authors’ answer:
It has been explained in the article. The main idea of ABAQUS calculation of crack growth is to define a bonding main surface and bonding slave surface, and define the node set on the bonding slave surface, so that the main surface and bonding slave surface are bonded together through these nodes, and then specify the bonding contact properties and fracture criteria. Under load or displacement loading, when the criterion critical value is reached, the node breaks away from the main surface. It can only be used for two-dimensional crack propagation. In abaqus software, the maximum normal stress criterion is used to judge the start of damage. When the ratio of stress to the critical value in any direction is 1, the initial damage point is reached.
3、The reviewer’s comments and suggestions:
Some phrases in the text of the article, which I considered stylistically incorrect, were not revised by the authors.
The authors’ answer:
Changes have been made to the statements in the article.
4、The reviewer’s comments and suggestions:
Links for formula 8 should be given in the article (not for the reviewer).
The authors’ answer:
All suggestions have been revised.
5、The reviewer’s comments and suggestions:
Line 129. Explain for the readers what is hard top plain.
The authors’ answer:
Not only the language of the article has been revised, but also the other opinions have been revised.
We have revised all the other comments you have marked in the article. Thank you and all the reviewers for the kind advice.
Yours Sincerely,
Professor Yuyang Wei, Minzheng Jiang, Xinyu Zhao, Xinrui Zhao, Kangxing Dong
Author Response File: Author Response.pdf
Round 3
Reviewer 5 Report
Line 292. The authors did not explain to readers what are sH , sn ,s h in the inequality s H <sn <s h
Author Response
Response to Reviewer
The first symbol means maximum horizontal stress, the second symbol means vertical ground stress, and the third symbol means minimum horizontal stress.
Author Response File: Author Response.pdf
