Operation State Evaluation of Miter Gate Based on On-Line Monitoring and Finite Element Analysis

Round 1

Reviewer 1 Report

This manuscript attempted to investigate the stress and crack propgagation of miter gates using online monitoring system, while finite element analysis is also presented. A few comments as follow:

1 In the Abstract section, it stated that "stress distribution law" and "crack expansion law" are studied, but not desribed in the manuscript. It will be interesting to readers if new laws are revealed.

2 Please consider if "the size of stress" can be improved.

3 It is recommended that the novelty of this manuscript be clearly stated in the Introduction section, as well as the structure of the whole manuscript.

4 Through there is FE analysis presented in the manuscript, but it seems that no findings/conclusions were found/derived from it. The remarks in the Conclusions are almost not affected if the FEA is not presented. It is suggested that the manuscript is logically organized.

5 It's gennerally suggested that it might be more interesting to the readers if the science of the investigation is properly revealed, which can benefit the whole community.

Author Response

Thanks very much for your kind comment, we have considered your

valuable suggestions and made the corresponding revisions.

• According to your suggestion, some descriptions about stress distribution and crack expansion are added in the manuscript. Because the actual sensor measurement results are usually interfered by some factors, we hope to verify the accuracy of the actual measurement by comparing the simulation results with the stress measurement results.
• Thanks for your comment about description “the size of stress”, and we modified it to “stress magnitude”
• We have modified the introduction section to state the novelty of this manuscript, which is marked in red.
• We have reorganized the discussions about FE in the manuscript, which are marked in red.
• Thanks for your comment. We tried our best to reorganize the manuscript to reveal the science of the investigation.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. In section 2.1, the authors give some sizes of the gate size. The authors had better give a picture or diagram to introduce it.

2. In section 2.2, the introduction about the monitoring system of miter gates should be in accord with the modules shown in the figure.

3 Some figures in this paper is unclear, like Figure 6. Besides, the legend.

4. The authors describe the crack propagation direction. The related images are suggested.

5. The paper looks like an experimental report. The authors should give deep explanation. For example, the relationship between the stress and crack studied in this study.

Author Response

Thanks very much for your kind comment, we have considered your

valuable suggestions and made the corresponding revisions.

• According to your suggestion, we have added the gate size in figure 2.
• Thanks very much for your suggestion. We have revised the introduction about the monitoring system sensors in accord with the modules shown in the figure 1.
• Thanks very much for your suggestion. We have revised some unclear figures.
• Thanks very much for your suggestion. Sorry for our failure to state clearly that the purpose of the paper investigation is to find the relationship of the stress and the crack of the miter gate, so as to prepare for the subsequent fatigue life analysis.
• Thanks very much for your suggestion. We strengthened the discussions of investigation, marked in red.

Author Response File: Author Response.pdf

Reviewer 3 Report

The manuscript entitled “Operation state evaluation of miter gate based on on-line monitoring and finite element analysis” is trying to study the stress distribution and crack propagation on a dam lock structure. However, the scientific story, implemented methodology, data analysis and discussion are both very ambiguous and disorganized, most of time, missing. There are many other critical issues in this manuscript:

1. The research objectives and background are not clear. There are so many terminologies left without sufficient explanations, leading to confusion and difficulties in understanding the manuscript.

2. The specific finite element simulation setup is not given. I don’t know how the authors do the simulation, what the material properties were using, how the authors applied boundary conditions. I don’t even know what the stress components are in figure 3.

3. The measured stresses and crack displacements were given without clear explanations. I don’t know what the curves (Figure 5, 6 and 8) mean or where those measurements were implemented.

4. The authors did not give enough description of the crack displacement measures in conjunction with their simulation results. They only mentioned that the crack observations are correlated with their stress analysis in the conclusion, without showing any proof or further discussion. I do not believe that the conclusions in this manuscript can be supported by their simulations or sensor observations.

5. There are significant amounts of grammar errors. The authors did not even bother to correct those errors before their submission. The sentences were just piled up together without any proper organizing.

 

This manuscript cannot express a clear idea of what they are doing. It can only cause confusion for readers. There are many grammar errors, typos, and unscientific words. I have listed specific comments below:

1. In the abstract, what do you mean “the stress distribution law” in Line 17. Also, what is the definition for “the size of stress”? You should use accurate scientific expressions from literature.

2. You should use Word software to correct grammar errors. For example, it should be “which bears …” rather than “which bear…” in Line 36. Also, you cannot have multiple sentences separated by comma (Line 47-54). Correct those errors across the whole manuscript.

3. In the introduction section, you mentioned the fiber-optic grating sensors. More information should be given for the benefits of readers, such as the working principles, the advantage or disadvantage of the technique, how to measure temperature, etc.

4. In the introduction, you have summarized some previous work. However, what is the contribution of your work over those published efforts. It is not clear to me at this point.

5. It seems that all the sentences are separated with commas. You should correct this grammar error.

6. Line 74-82, you describe the Gezhouba Dam No.2 lock as the research object. However, I still don’t know the structures of the dam lock after your description. Those terms such as main beams, partitions, or back ties, do not make any sense to me. You should have make a clear schematic of the dam lock to illustrate all the terms in your descriptions. Also why there is a symbol “▽” before the water level values?

7. Line 88: a schematic drawing of the miter gate operation should be given to illustrate the torsion deformation.

8. What do you mean “Strength Enhancement in 88 Fused Filament Fabrication via the Isotropy Toolpath Critical assessment of Shape Retrieval Tools].” in Line 88-90.  Why did you capitalize the words?

9. You talked about the complex state of force; however, it is still very elusive for the reader since there are so many unexplained terms. I suggest you rewrite the paragraph with any necessary schematics for a better understanding.

10. The fiber grating is generally used to measure displacement. How does stress be measured?

11. Line 112-118, there are so many unexplained objects, such as node plate, stiffening plate, gate shaft column, etc., which causes great confusions.

12. What do you mean “special support” in line 126 and line 128.

13. In figure 3, you showed 3 different conditions. However, what are the boundary conditions you used for the finite element simulations for the 3 conditions? What are the material properties? And what are the stress types for the contours you showed in Figure 3(b), (c) and (d)? Why do you want to study the 3 conditions?

14. There are a lot of grammar errors in line 163-165.

15. What are the stress components you are measuring from your stress sensors? Why do the stress curves drop from positive to negative in Figure 5? Is the stresses you measured the same with those carried by the structures?

16. Line 180, it is the first time you mentioned the stress is along the axial direction. What is the axial direction of stress? What is the point of plotting stress fluctuations along different locations in figure 6?

17. Line 191, what do you mean “the size of the force on the gate stresses”?

18. Line 198, what is the X-axis exactly? You said it is parallel to the water surface. However, don’t you know that there are infinite numbers of directions parallel to a surface?

19. In table 2, where are the sensors from LY60 to LY89 locating? What are the meanings of the first time, second time, etc. in table 2?

20. Why does the crack propagation displacement first increase and then decrease? Line 232, there is no sensor marked by color in table 2. In line 234, why are those specific sensors selected for analyzing crack state? Also, what do you mean “crack state”? These two words together can mean a broad range of things.

21. Why does the sensor LY89 have the largest displacement in Figure 9(b)? Is this consistent with the finite element simulation data? You have measured the crack displacement. However, you did not refer it back to your simulation results.

22. In your conclusion, you mentioned that “The crack width expansion is the largest on the lowermost layer”. However, you did not even talk about this layer in the manuscript. I do not believe that “The stress magnitude and crack width expansion are correlated” in line 274 without further discussion.

 

Author Response

Thanks very much for your kind comment, we have considered your

valuable suggestions and made the corresponding revisions.

• Sorry for not state clearly about the research objectives, and we perfected some discussions and terminology explanations, which are marked in red.
• Thanks for your comment. We have reorganized the discussions about FE in the manuscript and added the finite element simulation setup process and the material properties, which are marked in red.
• Thanks for your comment. The actual miter gate is so big that it needs a lot of sensors to measure the stress and the cracks. It is very difficult to analyze all sensors data, so we chose some sensor data according to actual historical records. We added some explanations about measured stresses and crack displacements and the curves (Figure 5, 6 and 8)mean.
• Thanks for your comment. We added the discusses about the relationship of sensor measurement results and simulation results, which also is added in conclusion.
• Thanks for your comment. We examined the whole manuscript and revised some errors.

 

Thanks very much for your kind comment, we have considered your valuable suggestions and made the corresponding revisions.

• Thanks for your comment and suggestion. We have corrected the wrong expressions.
• We have examined the whole manuscript and corrected the grammar errors.
• Thanks for your comment and suggestion. We added some contents about the fiber-optic grating sensors.
• We have added some contents about summary of some previous work in the introduction.
• We have examined the whole manuscript and corrected the grammar errors.
• We have added a figure to illustrate all the terms in our descriptions and the symbol“▽”represents the location is submerged under water.
• For large structural parts, it is common to induce large torsional deformations.
• Sorry for these words appearing, it is a fault because of type setting. We have corrected them.
• Thanks for your comment and suggestion. We revised and added some contents to explain the complex state of force.
• Fiber Bragg grating (FBG) technology is formed by using ultraviolet exposure technology to cause periodic changes of refractive index in the fiber core. Fiber Bragg grating (FBG) stress sensor is usually attached to an elastic body and protected with packaging. The wavelength of reflected light is very sensitive to temperature, stress and strain. When the elastic body is under pressure, the fiber Bragg grating and the elastic body will strain together, resulting in the shift of the peak wavelength of the reflected light of the fiber Bragg grating. The temperature, stress and strain can be sensed by measuring the wavelength shift.
• We have revised some expressions of the confused terms.
• "special support" in line 126 and line 128 is “specially made support”. We have correct it in the manuscript.
• We have added some contents about the finite element simulations. The 3 conditions is three different stress conditions in gate operation.
• We corrected the grammar errors in line 163-165.
• The pressure sensor measures the magnitude and direction of the stress at a certain position on the gate, so there are positive and negative values, which reflecting the direction of the gate deformation.
• The axial direction of stress is along the door shaft column direction, we have corrected it. Stress fluctuation is the difference between maximum stress and minimum stress at different locations. The stress distribution along the gate can be known by comparing the measurements of the sensors at different locations.
• We used the wrong expression in line 191, and we corrected it.
• The X-axis in line 198 is parallel to the water surface and along the miter gate.
• In table 2, the locations of the sensors from LY60 to LY89 is shown in Figure 7. The meaning of the first time, second time is the data collected at different time. We have explained it in the note under the table 2 in the manuscript.
• The force of the gate changes during the process of opening， closing the gate and flushing，discharging water in a working cycle, so the crack at the measurement place will be expanded and compressed. As the stress on the gate also changes with the change of seasons in which water level is different, the displacement fluctuation of crack growth first increases and then decreases during the data collection process.
• The displacement of the location of the sensor LY89 is the biggest, which is consistent with the finite element simulation results. We added to explain it in the manuscript.
• We have added the further discussion in the conclusion.

Thanks again for your profound comment and suggestion, it is greatly helpful to

improve our research and manuscript.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Many thanks for revising the manuscript and the efforts are appreciated. Further commenst as follow:

1 Writting can still be improved. For example, in Abstract, "...are main distributed..." and "The speed..."; in Introduciton, "...heavy failure...", "position of the sensor" and "the real time measuring signals combining with the finite element simulation model,..."; in section 2.2, the second "Fiber Bragg grating (FBG)"; in page 8, "the water filling and draining condition". Please further check other potential writting issues.

2 The online monitor system is consistent with the FE simulation at some level; it will be logically complete to offer specific advices based on the findings, which will be more useful to readers and make the manuscript more attractive.

Author Response

Thanks very much for your kind comment, we have considered your valuable suggestions and made the corresponding revisions.

(1) Thanks for your comment. We examined the whole manuscript and revised the errors.

(2) Thanks for your comment. This paper aims to judge the working state by the online monitoring and find the failure reason combining with the finite element analysis.

Author Response File: Author Response.docx

Reviewer 2 Report

The constraints of the miter gate should be marked in an additional figure, what causes the unbalanced stress distribution of the miter gate? Considering the loading and boundary conditions presented in the paper, the authors should explain the reason for unbalanced stress distribution.

The captions in some figures are too small to read clearly, for instance, figure 1 to figure 5.

In figure 5, the word “derection” means? Or it is a misspelling of the word “direction”?

In the last paragraph of Section 4, there are some grammar mistakes, for instance, there are wrong uses of single and plural numbers in the following sentences: “……the displacement of every crack propagation fluctuate a little in one year, and the data collected in the second time is biggest, which possible reason is seasonal water level fluctuations”, “……which indicate the direction of crack propagation from the bottom to the top of the crack.”

In the conclusion section, it says that “In this paper, the stress and strain distribution of the Gezhouba Dam 2# miter gate under closed, opening, filling and draining water conditions are calculated by using finite element.” However, there is no evidence of strain distribution or comparison in finite element analysis or crack signal analysis. Similar description is also found in the first paragraph of the section 3.3.

Author Response

Thanks very much for your kind comment, we have considered your valuable suggestions and made the corresponding revisions.

(1) Thanks for your comment and suggestions. The constraints and loads of the gate are shown in Figure 1, Figure 5 and Table 1. The miter gate is a huge steel framework, and the gate gravity great affects the stress distribution of the gate during opening and closing the door. At the same time, water level difference of front and back the gate is another important factor. Therefore, we analyse the gate state under different working conditions.

(2-4) Thanks for your comments and suggestions. We have checked the whole manuscript and corrected the errors.

(5) Thanks for your comment and suggestion. We just analyse the stress not the strain, so we delete the “strain” word in the paper.

Author Response File: Author Response.docx

Reviewer 3 Report

Here are some minor comments on the revised manuscript:

You added some contents about previous work in the introduction. However, it is still not clear what is your contribution to the literature. Summary of previous work is not enough.

The triangle symbol “▽” should be explained in the main text.

You added Figure 1 to explain the gate structure. However, there is not a single word in the main text body to describe it.

 

Author Response

Thanks very much for your kind comment, we have considered your valuable suggestions and made the corresponding revisions.

(1) Thanks for your comment and suggestion. We added the contribution of our work in the introduction.

(2) Thanks for your comment. We've reorganized the text in this paragraph and delete the "∇".

(3) Thanks for your comment. We add the single word in main text to describe it in 2.1.

Author Response File: Author Response.docx