Methods to Increase Fatigue Life at Rib to Deck Connection in Orthotropic Steel Bridge Decks
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors1. This article is devoted to the study of bridge weld fatigue. It is necessary to investigate ways to increase fatigue life at the rib-to-deck connections.
2. It is not appropriate to quote in full in the Introduction. American Society for Testing and Materials [3] defines 48 it as: "The process of progressive localized permanent structural change occurring in a 49 material subjected to conditions that produce fluctuating stresses and strains at some 50 point or points and that may culminate in cracks or complete fracture after a sufficient 51 number of fluctuations.” A reference to the source of [3] is sufficient.
3. It is not explained in detail how the ribs were technologically installed by two side welding to the decking sheet.
4. On the application of FEM. It is not clear from the text of the article how you model the fatigue phenomenon with Abaqus. A supplement is required.
5. It is not clear why the authors choose models of the appropriate size. There is no justification. After all, the accuracy of the results depends on it. That is why, e.g. the length of the large model is taken as 1.0 metres.
6. No comparative analysis of experimental studies according to Zhu et al. [24] and the results of FE calculations performed by the authors (Comparison of the calculated and tested results).
7. The figures must be of higher quality. For example, in Fig. 1 and other figures, the thickness of the dimension lines is the same as the thickness of the element lines. Also, the dimensions of all elements (thicknesses of sheets) etc. are not shown.
Author Response
- It is not appropriate to quote in full in the Introduction.American Society for Testing and Materials [3] defines 48 it as: "The process of progressive localized permanent structural change occurring in a 49 material subjected to conditions that produce fluctuating stresses and strains at some 50 point or points and that may culminate in cracks or complete fracture after a sufficient 51 number of fluctuations.” A reference to the source of [3] is sufficient.
Response: Thank you for your suggestion. This portion is updated as per your suggestion.
- It is not explained in detail how the ribs were technologically installed by two side welding to the decking sheet.
Response: Thank you for pointing out the issue. The outer welds in the ribs are installed manually by conventional methods but the welds inside the ribs are installed by welding Roberts. This information is added in section 2.1. The details on the process of welding; working mechanism of welding Robert and production of orthotropic steel bridge decks is beyond the scope of this research.
- On the application of FEM. It is not clear from the text of the article how you model the fatigue phenomenon with Abaqus. A supplement is required.
Response: Thank you for your constructive suggestion. We have added this information at the end of the introduction section along with the references. We appreciate your suggestion.
- It is not clear why the authors choose models of the appropriate size. There is no justification. After all, the accuracy of the results depends on it. That is why,e.g. the length of the large model is taken as 1.0 meter.
Response: Thank you for pointing this out. The deck and rib thickness and weld size are selected similar to the thickness deck and rib and the size of weld used in the real scenario. Obviously, the magnitude of concentrated stress depends on the magnitude of applied load and the size of the structure (i.e., dimension of the structure); but the pattern of stress concentration can be analyzed even with the models smaller than the actual models in the field. That is the reason why smaller models than the actual structures are tested and simulated in the laboratory (Dung et al. 2015 and Zhu et al. 2022). To remove the confusion the section heading is changed to: simulations of models similar to field structures.
- Dung C V, Sasaki E, Tajima K, and Susuki T. Investigation on the effect of Weld penetration on Fatigue Strength of Rib-to-Deck Joints in Orthotropic Steel Decks. International Journal of Steel Structures, 2015, 15(2), 299-310.
- Zhu A, Ouyang S, Chen Y, and Sun Y. Fatigue test and life evaluation of rib-to-deck connections in orthotropic steel bridge decks. Journal of Constructional Steel Research, 2022, 197, 107442.
In Finite Element Analysis, result accuracy depends on the chosen mesh size. Finer meshes yield higher precision. However, in this study, the mesh size used for numerical simulation is as small as 1 mm. Consequently, running large models with a 1 mm mesh size becomes impractical in real-world scenarios. Therefore, smaller models (ranging from 1 m to 3 m) are employed in this study.
The reasons for different kinds of model selection have been added section 2.1 and section 4 of the updated manuscript.
- No comparative analysis of experimental studies according to Zhu et al. [24] and the results of FE calculations performed by the authors (Comparison of the calculated and tested results).
Response: Section 5 is added in the updated manuscript where the simulated results are compared with test results.
- The figuresmust be of higher quality. For example, in Fig. 1 and other figures, the thickness of the dimension lines is the same as the thickness of the element lines. Also, the dimensions of all elements (thicknesses of sheets) etc. are not shown.
Response: We appreciate for bringing this up. We noticed that the quality of figures change and become blur once the manuscript is uploaded in the system which may be because of forced compression of high resolution image. All the lines’ thickness seems similar although they have different thickness. We will submit the original figures separately to the production team to ensure that the quality of the figures is maintained in the final version of the manuscript. The thickness of sheets is shown in the updated manuscript.
Finally, we would like to sincerely thank the reviewer for the valuable suggestions that helped to improve the quality of this manuscript significantly.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsNo comment.
Please see attached file.
Comments for author File: Comments.pdf
Author Response
Orthotropic steel bridges were a very popular design due to their simple construction technology and relatively low cost. The trend of building these bridges declined after the 1990s, mainly due to fatigue problems. The paper presented for review presents the results of numerical simulations for possible design solutions (using single and double fillet welds) in terms of fatigue analysis of the bridge. The analyses include the effects of weld fusion, deck thickness, rib thickness, and the combined effects of deck thickness, rib thickness, with single and double fillet welds. The parametric analysis consists of forty-two simulations. Among other things, it was found that thicker decks and thinner ribs are better for increasing fatigue life at rib-deck joints, and that increasing weld penetration slightly increases stress concentration. The article is well written, and the material in it can be helpful for preliminary work on the design of similar load-bearing structures.
Response: Thank you very much. We appreciate your feedback.
Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe topic is interesting but the conclusions are poor. Of course if you increase the thickness of the deck, the loads on stiffeners are low and the fatigue low. But this is known.
The authors should severally improve discussion and conclusions, otherwise the manuscript is not publishable.
Some figures need improvement in terms of clarity. Furthermore, the sections should be aligned to plan.
Comments on the Quality of English LanguageImprovements are needed
Author Response
The topic is interesting but the conclusions are poor. Of course if you increase the thickness of the deck, the loads on stiffeners are low and the fatigue low. But this is known.
The authors should severally improve discussion and conclusions, otherwise the manuscript is not publishable.
Some figures need improvement in terms of clarity. Furthermore, the sections should be aligned to plan.
Response: Thank you very much for your constructive suggestion. Your insightful comments and valuable suggestions played a crucial role in enhancing the quality of the manuscript. We have updated the discussion and conclusion. We noticed that once we upload the manuscript in the system the figures get blurred which may be because of forced compression of high-resolution image. We will submit the original figures separately to the production team to ensure that the quality of the figures is maintained in the final version of the manuscript.
Finally, we would like to sincerely thank the reviewer for the valuable suggestions that helped to improve the quality of this manuscript significantly.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsAccept
Comments on the Quality of English Languageminor
