Analysis of Optimal Loading Angle in Dynamic Flattened Brazilian Disc Splitting Test for Concrete
Round 1
Reviewer 1 Report
Reading your work, I found it very interesting. I spotted some errors in eq. (1) transferred from [28] and the lack of comparison of numerical and experimental data in a common diagram. Also, some check-in English must be done. Other minor changes:
· Add reference for Griffith Criterion:
Hoek, E., & Martin, C. D. (2014). Fracture initiation and propagation in intact rock - A review. In Journal of Rock Mechanics and Geotechnical Engineering (Vol. 6, Issue 4). https://doi.org/10.1016/j.jrmge.2014.06.001
· Also add the “new” direct test for concrete
Sarfarazi, V., Ghazvinian, A., Schubert, W., Nejati, H. R., & Hadei, R. (2016). A new approach for measurement of tensile strength of concrete. Periodica Polytechnica Civil Engineering, 60(2). https://doi.org/10.3311/PPci.8328
· Also, the review paper about direct tensile tests
Truong, V. D., & Kim, D. J. (2021). A review paper on direct tensile behavior and test methods of textile reinforced cementitious composites. In Composite Structures (Vol. 263). https://doi.org/10.1016/j.compstruct.2021.113661.
· You can add more references in line 38 for indirect tension.
· Give a sort definition for a bullet in line 89 (bullets, defined as kinetic energy penetrators).
· In line 92 change planar strain model into plane strain assumption.
· In eq.1 are some wrong transfers from [28] and you use c1 and C1 (with capital and with a small letter) which is correct. It’s better to put these equations into the appendix after carefully checking of their correctness.
· In the paragraph of lines 293-308 correct the figure reference number into Figure 14.
· In line 101 define JHC inside parenthesis.
· Table 1 is presented before the contents are described in the text; a nomenclature will be useful after the abstract.
· In line 160 begin with It is known.
· In line 202 wrong sign in f1=(σ1+3σ3)/…
· Also use a newer word equation editor the equation appears above the main text (in lines 202 and 207)).
· In line 215 what symbolizes the o-1 (also in 177, 183)
· In Figure 7 the smaller figure is σxx stress?
· In Figure 15 the points in curves are selected at the moment of crack initiation? It isn’t so clear in the text.
· In Figure 16 is better to put the platform angle in x-axis and stain the gauge number on the legend.
· There is no comparison figure of the experimental and numerical model (only qualitative Fig 3 and 14), you can put numerical predictions in Figure 16 (with lines).
Author Response
Dear Reviewers:
Thank you for the reviewers’ comments concerning our manuscript entitled “Analysis of optimal loading angle in dynamic flattened Brazilian disc splitting test for concrete” (ID: applsci-2040980). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have made corrections which we hope meet with approval. The main comments in the paper and the responses to the reviewers’ comments are as flowing:
Point 1: Add reference for Griffith Criterion:
Hoek, E., & Martin, C. D. (2014). Fracture initiation and propagation in intact rock - A review. In Journal of Rock Mechanics and Geotechnical Engineering (Vol. 6, Issue 4). https://doi.org/10.1016/j.jrmge.2014.06.001
Response 1: Thanks for the comments of the reviewer. The authors have added important references recommended by the reviewers.( see Lines 205 and Lines 513-514)
Point 2: Also, add the “new” direct test for concrete
Sarfarazi, V., Ghazvinian, A., Schubert, W., Nejati, H. R., & Hadei, R. (2016). A new approach for measurement of tensile strength of concrete. Periodica Polytechnica Civil Engineering, 60(2). https://doi.org/10.3311/PPci.8328
- Also, the review paper about direct tensile tests
Truong, V. D., & Kim, D. J. (2021). A review paper on direct tensile behavior and test methods of textile reinforced cementitious composites. In Composite Structures (Vol. 263). https://doi.org/10.1016/j.compstruct.2021.113661.
Response 2: Thanks for the comments of the reviewer. The authors have added important references recommended by the reviewers.(see Lines 49 and Lines 453-456)
Point 3: You can add more references in line 38 for indirect tension.
Response 3: Thanks for the reminder of the reviewer. The authors have added many important references on this topic. (see Lines 49 and Lines 457-464)
Point 4: Give a sort definition for a bullet in line 89 (bullets, defined as kinetic energy penetrators).
Response 4: Thanks for the reminder of the reviewer. The authors have replaced the ‘bullet’ with projectile throughout the manuscript in order to be consistent with Figure 1, also the definition of projectile was provided. (see Lines 101-102)
Point 5: In line 92 change planar strain model into plane strain assumption.
Response 5: Thanks for the reminder of the reviewer. The authors have replaced planar strain model with plane strain assumption. (see Lines 105)
Point 6: In eq.1 are some wrong transfers from [28] and you use c1 and C1 (with capital and with a small letter) which is correct. It’s better to put these equations into the appendix after carefully checking of their correctness.
Response 6: Thanks for the reminder of the reviewer. The authors have double-checked this formula and use a small letter c1 in all the equations, that has been corrected in the appendix as well. (see Lines 525-527)
Point 7: In the paragraph of lines 293-308 correct the figure reference number into Figure 14.
Response 7: Thanks for the reminder of the reviewer. The authors have corrected the figure reference number into Figure 14. (see Lines 299-319)
Point 8: In line 101 define JHC inside parenthesis.
Response 8: Thanks for the reminder of the reviewer. The authors have defined JHC inside parenthesis. (see Lines 117)
Point 9: Table 1 is presented before the contents are described in the text; a nomenclature will be useful after the abstract.
Response 9: Thanks for the reminder of the reviewer. The authors have adjusted this. Also add a nomenclature of terms after the abstract (see Lines 112 and see Lines 29)
Point 10: In line 160 begin with It is known.
Response 10: Thanks for the reminder of the reviewer. The authors have made changes to this. (see Lines 179)
Point 11: In line 202 wrong sign in f1=(σ1+3σ3)/…; also use a newer word equation editor the equation appears above the main text (in lines 202 and 207)).
Response 11: Thanks for the reminder of the reviewer. The authors have corrected this error and used a newer word equation editor the equation appears above the main text. (see Lines 213 and Lines 219)
Point 12: In line 215 what symbolizes the o-1 (also in 177, 183)
Response 12: Thanks for the reminder of the reviewer. The authors have removed this symbol, in order to be more standardized, again without affecting the effectiveness of the expression. Descriptive language is used to express the relationship between dimensionless quantities as the loading angle changes. (see Lines 194 and see Lines 228)
Point 13: In Figure 7 the smaller figure is σxx stress?
Response 13: Thanks for the reminder of the reviewer. The small figure in Figure 7 represents σy stress, which is specially labeled by the authors for a clearer representation. (see Lines 237)
Point 14: In Figure 15 the points in curves are selected at the moment of crack initiation? It isn’t so clear in the text.
Response 14: Thanks for the reminder of the reviewer. The authors have explained it in more detail. Although Figure 15 is always increasing, there is still a steep increase in strain at the time of its destruction, but the data points are too dense to be easily seen on the graph. The strain value of the mutation point can be accurately identified in the raw data text. Since the sampling frequency of the dynamic acquisition instrument is set to 2MHz, the strain value corresponding to each time can be seen in the raw data text. By importing the data into origin in the form of a picture that cannot be easily discriminated, the mutation point can be easily identified through the raw data text. The strain history curves measured in the test can be used to analyze the crack initiation and expansion characteristics of dynamic splitting specimens. A series of resistive strain gauges are pasted on the specimen surface in the direction of the loading diameter to record the strain variation curve of each point on the specimen loading diameter with time. (see Lines 330- 333)
Point 15: In Figure 16 is better to put the platform angle in x-axis and stain the gauge number on the legend.
Response 15: Thanks for the reminder of the reviewer. The authors have adjusted this. (see Lines 379)
Point 16: There is no comparison figure of the experimental and numerical model (only qualitative Fig 3 and 14), you can put numerical predictions in Figure 16 (with lines).
Response 16: Thanks for the reminder of the reviewer. The suggestion of comparing the experimental and numerical results is really a good idea, however, after Figure 16 being transformed according to comment 15, it was found that the results of the numerical simulation turned out to be only a straight line that parallel to y axis.
Nevertheless, the authors have added the DIC results of the loading angle of 0° in Fig 14, i.e., the conventional Brazilian splitting disc test, and found that the numerical simulation results and the experimental results are still in high agreement. By comparing Fig. 3 and 14, we believe it is able to show the consistency between numerical simulation and experimental results.
Reviewer 2 Report
The authors studied the optimal loading angle in the dynamic flattened Brazilian disc splitting test for concrete. The work is of average novelty level. However, there are some comments that need to be covered before recommending this article for publication in Applied Science. The comments are as follows:
1- In the introduction section, I recommend mentioning previous studies done on the effect of blast loading on different RC members (beams, columns, slabs, silos, … etc.) and relating it to the severe tensile damage that occurred in concrete. I recommend the following references:
- Temsah, Y., Jahami, A., Khatib, J., & Sonebi, M. (2018). Numerical analysis of a reinforced concrete beam under blast loading. MATEC Web Of Conferences, 149, 02063. doi: 10.1051/matecconf/201814902063.
- Temsah, Y., Jahami, A. and Aouad, C. (2021). Silos structural response to blast loading. Engineering Structures, 243, p.112671. DOI: 10.1016/j.engstruct.2021.112671.
2- You mentioned that you used the JHC model for modeling concrete subjected to high strain rates. It would be better to refer to other studies that used the same material model in impact load simulations.
3- The paragraph (lines 115-153) is too long. Divide it into several paragraphs each with a maximum of 10 lines. Do the same for the whole manuscript.
4- Add a recommendation section for future research based on your findings.
5- Check the whole manuscript for some typos and grammatical mistakes.
Author Response
Dear Reviewers:
Thank you for the reviewers’ comments concerning our manuscript entitled “Analysis of optimal loading angle in dynamic flattened Brazilian disc splitting test for concrete” (ID: applsci-2040980). Those comments are all valuable and very helpful for revising and improving our paper, as well as the important guiding significance to our research. We have studied the comments carefully and have made corrections which we hope meet with approval. The main comments in the paper and the responses to the reviewers’ comments are as flowing:
Point 1: In the introduction section, I recommend mentioning previous studies done on the effect of blast loading on different RC members (beams, columns, slabs, silos, … etc.) and relating it to the severe tensile damage that occurred in concrete. I recommend the following references:
- Temsah, Y., Jahami, A., Khatib, J., & Sonebi, M. (2018). Numerical analysis of a reinforced concrete beam under blast loading. MATEC Web Of Conferences, 149, 02063. doi: 10.1051/matecconf/201814902063.
- Temsah, Y., Jahami, A. and Aouad, C. (2021). Silos structural response to blast loading. Engineering Structures, 243, p.112671. DOI: 10.1016/j.engstruct.2021.112671.
Response 1: Thanks for the reminder of the reviewer. The authors have revised the introduction section as suggested by the reviewers. (see Lines 30-45)
Point 2: You mentioned that you used the JHC model for modeling concrete subjected to high strain rates. It would be better to refer to other studies that used the same material model in impact load simulations.
Response 2: Thanks for the reminder of the reviewer. The authors have cited other studies [1,2] that have used the same material model in impact load simulations. (see Lines 117)
[1]Kucewicz, M.; Baranowski, P.; Malachowski, J.Dolomite fracture modeling using the Johnson-Holmquist concrete material model: Parameter determination and validation. Journal of Rock Mechanics and Geotechnical Engineering 2021,13,335-350.
[2] Pajak, M.; Baranowski,P.; Janiszewski, J.Experimental testing and 3D meso-scale numerical simulations of SCC subjected to high compression strain rates. Construction and Building Materials 2021,302.
Point 3: The paragraph (lines 115-153) is too long. Divide it into several paragraphs each with a maximum of 10 lines. Do the same for the whole manuscript.
Response 3: Thanks for the reminder of the reviewer. The author has shortened the number of lines in paragraphs throughout the text.
Point 4: Add a recommendation section for future research based on your findings. Response 4: Thanks for the reminder of the reviewer. The authors have added a future research. (see Lines 417-423)
Point 5: Check the whole manuscript for some typos and grammatical mistakes.
Response 5: Thanks for the reminder of the reviewer. The authors have carefully proofread this paper in English.
Author Response File: 
Author Response.doc
Round 2
Reviewer 2 Report
The article is recommended for publication in the Applied Sciences Journal
