Research on the Local Damage Characteristics of Steel Box Girder Structures Under the Effects of Explosive Shock Waves

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study examines the local damage behavior and influencing factors of steel box girder structures subjected to explosive shock waves. A 1:1 numerical model of a steel box girder is employed, with its accuracy confirmed through comparison to experimental results from a 1:10 scaled explosion test. Findings indicate that local damage predominantly impacts the top plate, base plate, and internal partitions, with the top plate experiencing the most severe effects. The explosion's location plays a critical role in damage severity, with regions lacking transverse and longitudinal partitions showing a 50-70% increase in damage compared to partitioned areas. Stiffening ribs reflect shock waves, leading to crack displacement in the base plate, which is further aggravated by increases in TNT equivalent. The study highlights the importance of incorporating the protective benefits of partitions and stiffening ribs in the structural design of steel box girders.

The article exhibits a well-organized structure and clear presentation. The writing is understandable, although it is apparent that the authors are not native English speakers. Overall, the results are effectively communicated, and the topic is both intriguing and promising.

1.      The title is overly long and could be more effective. The reviewer suggests shortening it to enhance clarity and communication.

2.      The first sentence of the abstract is unclear, and it should be rewritten.

3.      In the abstract, "On the basis of model validation of the explosion test values of the 1:10 scaled-down model of steel box girder, a 1:1 numerical model of the steel box girder structure was established." should be replaced with "Based on the model validation of the explosion test values of the 1:10 scaled-down model of the steel box girder, a 1:1 numerical model of the steel box girder structure was established."

4.      Overall, the abstract is not well-written and requires improvement. As one of the most critical sections of a scientific paper, the abstract serves as the primary introduction of the work to potential readers. Therefore, it is essential to craft a clear, concise, and impactful abstract to effectively convey the key aspects of the study.

5.      In the introduction it is necessary to introduce a paragraph to describe the structure of the paper and guide the interested readers into the reading process.

6.      The primary limitation of the study is that the experiment was conducted solely on a steel box girder, without accounting for the effects of other materials typically present in a real bridge. Given the presence of the deck and various layers in an actual bridge, it is unlikely that the explosion load would behave in the same manner as in the experiment. The authors are requested to provide a more detailed explanation of the experimental design and offer a clear justification for this omission.

7.      In the introduction, can be useful to introduce a paragraph dedicated to different damaging conditions in steel bridges. Some references can be found in the following:

a.      Rosso, et al. (2023, August). Noise effects analysis on subspace-based damage detection with neural networks. In Structures (Vol. 54, pp. 23-37). Elsevier.

b.      Biezma, M. V., & Schanack, F. (2007). Collapse of steel bridges. Journal of Performance of Constructed Facilities, 21(5), 398-405.

8.      Please add a reference for the conversion to TNT equivalent.

9.      The punctuation throughout the paper requires a thorough revision. Symbols other than standard full stops and commas are frequently used, which should be corrected for clarity and consistency.

10.   Please use math notation in the text. For example, “E_0” should be reported in the text as “E₀” to match the notation in the formulas.

11.   In Figure 4a, the text is too small to be easily readable. Please increase the font size to ensure that readers can clearly understand the dimensions of the box girder.

12.   While the study appears to be innovative, it lacks originality and broader applicability. The authors conducted an experimental test and compared the results with a numerical study; however, no effort has been made to explore how the numerical methodology could be generalized or how the findings could be practically applied in real-world scenarios. The reviewer recommends addressing these aspects in greater depth before the paper can be considered for publication.

In conclusion, the paper is deemed interesting, and the reviewer recommends it for publication after the requested major revisions are addressed.

Comments on the Quality of English Language

The writing is understandable, although it is apparent that the authors are not native English speakers.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The reviewed work is quite an interesting topic. I believe that introducing a graphic representation of cases (location) would complement the work. The title is quite long. There is some chaos and editing errors in the work. It is worth reading the entire work again calmly in order to eliminate these errors.

There are no spaces in many places, e.g. line 49 - al. [4]simulated

Lines 121 - description in brackets including '_': (It employs high-energy combustion model explosives（High_ Explosive_ Burn），

Line 125 legend and description of variables E_0

are the following records necessary: ​​Mat_ Null model and the Eos_ Linear_ Polynomial?

in the first occurrence, include the full name: relationship of steel is the J-C model, JWL equation

"Figure 1. Experimental and simulation models. (a) Experimental apparatus and explosion process. (b) Simulation mode." a schematic drawing would be useful. Unfortunately, it is not possible to read everything well from the photo and the sketch of the numerical model.

Figure 10. Damage pattern of steel box girder (Location 33, damage modes II and III, unit: kg). - location 33 and the load value was not entered on the graph.

Figures 9 and 10 could be supplemented with cross-sections.

Line 331: stiffening rib, etc. There are differences.

Lines 362-372: "The results show that: with the rise of TNT equivalent, the range of cracks in the top plate under the explosion load is also expanding, but the expansion trend is gradually slowing down, which is due to the following reasons: firstly, because of the increase of TNT equivalent, the shock wave arrives at the top plate earlier and faster to produce the cracks faster, resulting in the rapid propagation of the shock wave through the cracks and manholes inside the steel box girder, and secondly, the resisting effect of the spacer plate and the stiffening ribs in the steel box girder." - it's one sentence. Please provide a thematic breakdown. Very difficult to read.

Line 398: "at the two" - both locations.

Line 414: crack location is not symmetrical, and the size of the cracks, - and the size of the cracks what?

Line 420: the shock wave directly to the base plate ?

Bibliography: I am not familiar with the [J/OL] designations, please explain.

Questions for the paper:

1. You are only investigating the issue of a sudden explosion of a charge and damage to the bridge. The duration of the study is 30 ms. Do you plan to extend your research to include a dynamic analysis of the bridge? or a post-critical analysis.

2. How would such damage affect the stability of the object.

3. Figures 11, 12, 14 have combined results suggesting linearity between these relationships. Is this assumption correct?

Comments on the Quality of English Language

Introducing multiple compound sentences can cause a lot of chaos. I suggest editing to simplify explanations of issues by breaking sentences into shorter ones. There are also sentences that do not make sense (examples introduced in the review).

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors correctly addressed all the reviewer's comments, therefore the paper is suitable for the publications.

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for your comprehensive responses to all comments. The current version of the article contains all necessary additions and corrections.

In its current version, the article can be published.