Optical Fiber-Based Structural Health Monitoring: Advancements, Applications, and Integration with Artificial Intelligence for Civil and Urban Infrastructure

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This review article presents a comprehensive overview of optical fiber sensing technologies in structural health monitoring, with a focus on recent advancements, practical applications, and the integration of AI. but the manuscript should be improved. Please see below my comments.

1. The key infrastructure domains, not only including bridges, tunnels, high-rise buildings, pipelines, and offshore structures, but also including slope/ foundation ditch and roadbed/ roadway/ train track and so on. Please supplement relevant cases.
2. A single case placed in the first paragraph on the second page seems rather abrupt and thin. Please enrich the content or optimize the manuscript structure.
3. The advantages of OFSs in SHM demonstrate in Table 2 are too absolute. For example, MEMS sensors have a smaller volume; With the development of electrical technology, digital signal sensors can still be used in series, the electrical sensor with digital signal can also monitor multiple points along a single cable. The comparison should be objective and fair. It is not advisable to merely contrast the advantages of optical fiber sensing with the disadvantages of electrical sensing. Compared with traditional sensors, in terms of technological maturity, installation survival rate and cost, optical fiber sensing technology does not have obvious advantages. Traditional electrical sensors can also provides continuous, real-time monitoring of structural health.
4. The content of the review is too scanty in Section 3. The case descriptions are overly detailed and there are too few cases, especially for 3.1 and 3.2.
5. All of the contents related to fundamentals of OFSs in Section 3, such as the second paragraph and the third paragraph in page 9, should be placed in the Section 2.
6. The content of the third paragraph in page 10 is almost the same as that of the second paragraph in page 2.
7. The Section 6 is not closely related to fiber optic sensing.
8. It is difficult to determine the type of structural damage based on a single monitoring parameter. Intelligent identification of unknown damage based on multi-parameter monitoring is one of the future research directions.

Author Response

We sincerely thank you for your thoughtful and constructive feedback on our manuscript. Your detailed comments and suggestions have been instrumental in helping us improve the quality and clarity of our work. We have carefully considered each of your points and made corresponding revisions throughout the paper to address your concerns. In particular, we have revised the relevant sections to improve the coherence of the arguments, clarified key methodological details, and ensured that the results are presented more clearly and thoroughly. We believe that these revisions have significantly strengthened the manuscript, and we are grateful for the opportunity to enhance our work based on your insights.

The attached file contains our detailed answers.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This review article offers a thorough and well-structured exploration of optical fiber-based structural health monitoring (SHM). The figures and text are generally clear, and there are no major issues that need to be addressed.

Author Response

We are grateful to the reviewer for the positive assessment of our work.

Reviewer 3 Report

Comments and Suggestions for Authors

This manuscript provides a review of Distributed Acoustic Sensing (DAS) technology for the perception of vehicle status information. The authors have commendably compiled a broad overview covering sensing principles, influencing factors, signal processing techniques, and applications related to DAS for vehicle monitoring. However, while comprehensive in breadth, the review currently lacks the depth and critical analysis. To elevate the manuscript’s contribution, a more profound analysis, potentially incorporating quantitative comparisons where possible and a more forward-thinking perspective grounded in the fundamental physics and signal processing challenges, is needed. The English expression, while generally understandable, requires refinement for clarity, precision, and academic rigor. Here are some suggestions:

1. The Introduction could more explicitly state the novelty of this specific review compared to existing reviews on DAS in general or reviews on traffic sensing using other modalities. What unique perspective or scope does this paper offer?
2. Section 3.2 discusses correlations qualitatively. While noting the literature gap is valid, the authors could hypothesize why a quantitative understanding is difficult (e.g., complex multi-physics coupling, heterogeneous road materials, varying vehicle dynamics, environmental noise variability) to frame the challenge more precisely.
3. Regarding the “Heterogeneous sensing technology” future direction (Section 5.3), specifying which modalities (e.g., cameras, radar, loops) would be most complementary to DAS for different types of information (e.g., visual classification, precise speed/length, point detection confirmation) could add valuable detail.
4. Proofread the manuscript thoroughly for any remaining grammatical errors, typos, or awkward phrasing that might detract from the clarity and professionalism expected of a high-level publication. For example, review sentences like “realize the aspiration of ‘people enjoying their travel and things flowing smoothly’” for formality in a technical context.

Author Response

We sincerely thank you for your thoughtful and constructive feedback on our manuscript. Your detailed comments and suggestions have been instrumental in helping us improve the quality and clarity of our work. We have carefully considered each of your points and made corresponding revisions throughout the paper to address your concerns. In particular, we have revised the relevant sections to improve the coherence of the arguments, clarified key methodological details, and ensured that the results are presented more clearly and thoroughly. We believe that these revisions have significantly strengthened the manuscript, and we are grateful for the opportunity to enhance our work based on your insights.

File with detailed responses to comments is attached.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Although the author has made many improvements, the current version is still not a satisfactory manuscript.

1. What are the key infrastructure domains? How is key infrastructure domains defined? Offshore platforms and wind turbines are usually located far away from cities. Accurate classification forms the basis for a clear article structure.
2. The introduction part is not a detailed discussion of one or two cases, but a high-level generalization and summary
3. Regarding the fifth point, The author said “Thank you for the valuable suggestion. However, we realize that those paragraphs relate to section 3, therefore, it is better to keep them as it is.” I do not understand the author's meaning.
4. What does "DL" mean? Deep learning?

Author Response

Dear Reviewer,

We sincerely thank you for your thoughtful and constructive feedback on our manuscript. 

We have carefully considered each of your points and made corresponding revisions throughout the paper to address your concerns. We believe that these revisions have significantly strengthened the manuscript, and we are grateful for the opportunity to enhance our work based on your insights.

Detailed answers in the attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

I find that the authors have put considerable effort into addressing the reports of the referees. The authors have made sufficient modifications according to the modification comments. 

Author Response

We are grateful to the reviewer for his constructive comments and positive assessment of the revised manuscript.

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Although the author has made many improvements, I think the structure of the manuscript still needs to be optimized:

1. An excellent article must first have a corresponding title. In short, the content should be consistent with the title. We all know offshore platforms and wind turbines are geographically distant from urban centers, the title should not be limited to “in smart cities”. Not only dams and offshore platforms, but also slopes and highways have play an essential role in civil and urban systems by supporting transportation, energy generation, water distribution, and large-scale human habitation. Therefore, I’m strongly recommended to modify the title or structure of the manuscript.
2. All optical fiber sensing technologies (including FBG and BOTDA) are universal and can be used not only for tunnel monitoring but also for bridge monitoring and so on. It is inappropriate to only introduce BOTDA technology in the tunnel section 3.2, all of the contents related to fundamentals of OFSs should be placed in the Section 2. Or, according to the differences among tunnels, Bridges, dams and so on, the differentiated applications of optical fiber sensing technology in each structure are introduced in detail respectively.

Author Response

We appreciate the reviewer’s thoughtful and constructive feedback regarding the alignment between the manuscript title and its content. We have taken the comments into account. The detailed answer in the attachment.

Author Response File: Author Response.pdf