Coupling Study of Deformation Field Evolution and Acoustic Emission Response Characteristics in Rock Failure and Instability Process

Round 1

Reviewer 1 Report

Study on the characteristics of deformation field evolution and acoustic emission response of rock failure and instability process. In this paper, acoustic emission and digital image coupling localization technology are used to identify the fracture process zone and fracture mechanism of rock, which provides a new technical means for further research on mechanical properties of rock materials. However, the following items need to be modified:

 Question 1: The time of stress drop in the stress curve in Fig.6 and Fig.7 is obviously earlier than the acoustic emission signal, and the author should give a detailed explanation.

Question 2: The AE cumulative ringing count curve and cumulative energy curve in Fig.8 are masked by text. It is recommended to modify the text format in the legend to make the curve appear.

Question 3: Fig.9 (e) is not clear enough. It is recommended to improve the clarity of the picture or mark the cracks.

Question 4: In Section 5.2, the text mentioned that red represents large acoustic emission energy, so the author should explain in detail whether red, green, yellow and blue in Fig.11 have different energy intensities of acoustic emission signals.

Question 5: The color display in Fig.11 (b) is confused, and the positioning point information cannot be obtained intuitively. The author should adjust this.

Question 6: The fourth conclusion is the evaluation of your work, which should not be included in the conclusion. It is suggested to delete or make some adjustments.

Author Response

Thanks for the expert advice, please refer to the attachment for the specific modification.

Author Response File: Author Response.docx

Reviewer 2 Report

-The manuscript should be changed from an article to a "Technical Note" as most of what has been presented is of general knowledge, and the only new point is the incorporation of DIC.

-The length of the manuscript can be reduced as some descriptions are repeated. For example, section 3.2 is explained first at the beginning of section 2. Then, remove ALL paragraphs or sections that are repeated. This will make the manuscript more concise and easy to digest for the reader.

-Since DIC was incorporated to this study, make a discussion section on how the results correlate with results or studies presented by others. Contrast your results with those presented by others and suggest practical applications.

-Others.
Enrich the captions for each figure. Try to include more details and descriptions to guide the reader understand the main points.

Author Response

Thanks for the expert advice, please refer to the attachment for the specific modification.

Author Response File: Author Response.docx

Reviewer 3 Report

This paper studies rock instability failure fractures using acoustic emission and digital image correlation. The paper claims to show a correlation between the two. However, the figures are not showing much data supporting the claim. Also, the number of samples tested is not specified implying that only one sample was tested.  The paper needs to be improved before it may be considered for publication. See my comments attached.

Comments for author File: Comments.pdf

Author Response

Dear Editor/Reviewers:

Thank you very much for your evaluation of our manuscript sustainability-1979025 entitled “Study on the characteristics of deformation field evolution and acoustic emission response of rock failure and instability process”. We appreciate the comments that are all very helpful for improving our paper and have an important guiding significance to our research. We have studied the comments carefully and revised them. Please see below a list of revisions and attachments that address all the points raised by the reviewers.

Reviewer Comments

This paper studies rock instability failure fractures using acoustic emission and digital image correlation. The paper claims to show a correlation between the two. However, the figures are not showing much data supporting the claim. Also, the number of samples tested is not specified implying that only one sample was tested.  The paper needs to be improved before it may be considered for publication. See my comments attached.

Response:

Thank you very much for your careful correction and valuable suggestions. Based on your comments and the amendment suggestions in the attachment, we have revised the full paper and explained the following important issues.

By using the experimental method presented in this paper, the AE and speckle experiments of five specimens during uniaxial loading were carried out. Due to the similar test results and experimental rules of the five specimens, this paper only analyzed the representative specimens R-1-4 due to the limited length.

Question 1. Title of the paper is not very clear, improve it to attract audience.

Response:

To make the title of the paper clearer, we have changed the title to " Coupling study of deformation field evolution and acoustic emission response characteristics in rock failure and instability process".

Question 2. Reinforce introduction with the help of recent publications.

Response:

According to your suggestion, some high level and familiar references had been cited in our paper. Such revisions could be found in following pages:

Line 39:

3. Bu, F.;Xue, L.;Zhai, M.;Huang, X.;Dong, J.;Liang, N.;Xu, C., "Evaluation of the characterization of acoustic emission of brittle rocks from the experiment to numerical simulation". Scientific Reports, 2022, 12(1): 1-16.

Line 57:

4. Liu, X.; Han, M.; Li, X.; et al., "Elastic wave attenuation characteristics and relevance for rock microstructures". Journal of Mining Science, 2020,vol. 56, no. 2, pp. 216-225.
5. Zhao, Y.; Li, B.; Zhang, C.; et al, "Experimental study on charge induction and microseismic laws of coal and rock with different combination ratios". J. Saf. Sci. Technol, 2019, vol. 15, pp. 107-112.
6. J. Li, "Research on the application of acoustic emission intelligent monitoring and early warning technology for the coal-rock dynamic disasters in underground mining faces," in IOP Conference Series: Earth and Environmental Science, 2020, vol. 526, no. 1: IOP Publishing, p. 012121.

Line 84:

16. G. M. Hassan, "Deformation measurement in the presence of discontinuities with digital image correlation: A review," Optics and Lasers in Engineering, 2021,vol. 137, p. 106394.

Line 108:

27. Hu, X.; Gong, X; Hu, H.; et al, "Cracking behavior and acoustic emission characteristics of heterogeneous granite with double pre-existing filled flaws and a circular hole under uniaxial compression: Insights from grain-based discrete element method modeling," Bulletin of Engineering Geology and the Environment, 2022,vol. 81, no. 4, pp. 1-24.

Question 3. Whether the text should be added to the list of abbreviations.

Response:

Abbreviations in the text include DIC and AE, both of which are fully explained in the abstract. So there's no need for a separate list of abbreviations.

Question 4. Is DS5-8B used to study rocks?

Response:

DS5-8B acoustic emission instrument is produced by China Beijing Soft Island Times Technology Co., LTD. As a commonly used coal and rock acoustic emission signal monitoring system in China, most of the functions are the same as the traditional acoustic emission monitor, but there are technical innovations in some details.

Question 5. Why we see a quiet period?

Response:

Stress peak in the late of specimen damage, beginning of the formation of a large number of cracks, continue to exert load, crack closure gradually, in the process, the acoustic emission signal is weak, when cracks closed completely, specimen into the residual strength failure stage, to continue in the process of the applied load, instability and failure of specimen thoroughly, accompanied by a large number of acoustic emission signal, therefore, The AE response will enter a quiet period.

Question 6. Regarding the expert opinion of Figure 11 in the first draft, which is now Figure 10, we give the following explanation.

Response:

Figure 11 shows the evolution characteristics of the principal strain field and the spatial distribution of acoustic emission positioning events corresponding to typical moments in the whole loading process. Figure (a) shows the evolution characteristics of the principal strain field in the whole process, and Figure (b) shows the evolution characteristics of the spatial distribution of acoustic emission positioning events at the same time. Through comparative analysis of Figure (a) and Figure (b), it can be seen that the main strain field forms a "y" shaped localized band, which penetrates the whole specimen and expands along the crack path, and the strain reaches the maximum value. At this time point, the acoustic emission event spatial positioning point reaches the peak, which is distributed throughout the specimen along the crack direction, and the spatial distribution shape is similar to the "y" shape.

Question 7. Regarding the expert opinion of Figure 13 in the first draft, which is now Figure 12, we give the following explanation.

Response:

Based on DBSCAN clustering algorithm for clustering analysis of acoustic emission data processing, is more intuitive to reflect the characteristics of the spatial distribution of ae location events and the deformation localization band coupling relations, only the path on the deformation localization band ae location events within the scope of the projection to the two-dimensional in-plane deformation image overlay, and eventually display as shown in figure 13. Among them, the figure shows that the shape size of the cluster symbol indicates the energy size of the microseismic event, the larger the shape, the larger the energy, and vice versa. The clustering results show that the distribution law of large energy events is basically consistent with the evolution path of the localized zone, which plays a decisive role in the failure and instability of the rock.

Finally, thank you very much for your kind work and advices again. On behalf of my co-authors, we would like to express our great appreciation to editor and reviewers. Best wishes to you all!

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Authors have carefully reviewed the manuscript and have answered to all the questions raised. 
The manuscript in the present form is an enhancement to the existing knowledge can be published in the journal.