Shear Behavior of Stud-PBL Composite Shear Connector for Steel–Ceramsite Concrete Composite Structure
Round 1
Reviewer 1 Report
The authors have experimentally and numerically investigated the performance of shear Studs and Perfobond Leiste (PBL) composite shear connector behavior for concrete composite structure. While the topic is interesting and the model has some merit, the overall manuscript does need more additional works to rise to the level of publication in the Journal of Coatings in the opinion of this reviewer. Below are just some minor comments and suggestions for improvement. Some suggestions for the current manuscript are as follows:
- The introduction lists some relevant research but fails to present a scientific review. Please consider to rewrite and clarify the motivation, objectives, and significance of this study.
- In order to better evaluate the advantage of using the system, comparing test results with code estimated capacities is recommended. I would suggest comparing the shear for the tested specimens with estimated code design values.
- The conclusion needs to be refined; it looks like a discussion. Design recommendations and feasibility need to be discussed further.
- Please add a new section for more discussion on the capacity, such as strength and deformation capacity. A simple comparison between the specimens is not enough, to explain how to evaluate the capacity based on existing knowledge or propose your assessment method is of interest to the readers of the journal.
- In the manuscript, there is not any calibration or validation of the models with an experimental data. the reviewer did not find any calibration process in the body of this manuscript. If there was calibration, the authors should provide all information about calibrated parameters. The calibration and validation process should be conducted in this research and demonstrated the applicability of the model in analyzing condition of different condition. This verification process helped to calibrate the proposed model and to make adjustments to the parameters used in the model.
- The Finite element models for concrete and other materials require a large amount of information. The authors depended in their simulations on several perimeters that some of them obtained from past research and others assumed by the authors. Due to this lack of information, the results from the finite element models presented in the paper is a bit questionable. In general, the manuscript still requires additional revisions in the evaluation of the models presented.
Author Response
Response to Reviewer 1 Comments
- The introduction lists some relevant research but fails to present a scientific review. Please consider to rewrite and clarify the motivation, objectives, and significance of this study.
Response: We have re-read the introduction carefully and found that the motivation, purpose and significance of the research in this paper are indeed not clarified, as you pointed out. We have revised the introduction as you suggested. The revised section was in red font.
- In order to better evaluate the advantage of using the system, comparing test results with code estimated capacities is recommended. I would suggest comparing the shear for the tested specimens with estimated code design values.
Response: We have revised as you suggested. The revised section was in purple font.
- The conclusion needs to be refined; it looks like a discussion. Design recommendations and feasibility need to be discussed further.
Response: This is a very excellent comment. First，we thought it was feasible to use finite element simulation to reveal the force mechanism of the composite shear connector and perform parametric analysis，because the analysis results were in good agreement with the experimental phenomenon, load–slip curve, and shear bearing capacity of the push-out test. Then, we added the optimal structural combination parameters of the composite shear connector as design recommendation. Finally, we pointed out that the shear bearing capacity calculation formula of this study could be applied in actual engineering, because the safety factor needed to be considered in the actual project, and the formula calculation value was conservative compared with the actual measured value. All of the above sections were revised in red font in the conclusion section.
- Please add a new section for more discussion on the capacity, such as strength and deformation capacity. A simple comparison between the specimens is not enough, to explain how to evaluate the capacity based on existing knowledge or propose your assessment method is of interest to the readers of the journal.
Response: First of all, we need to apologize to you, because we just added a paragraph to summarize section 2.3. We pointed out that the composite shear connector has excellent deformation capacity while having the highest shear bearing capacity and stiffness. This still relied on the magnitude of the values, which might not meet your expectations. Then, we would like to thank you for bringing new research ideas to us. Creating a reasonable method for evaluating shear connectors, it will be the focus of our later research.
- In the manuscript, there is not any calibration or validation of the models with an experimental data. the reviewer did not find any calibration process in the body of this manuscript. If there was calibration, the authors should provide all information about calibrated parameters. The calibration and validation process should be conducted in this research and demonstrated the applicability of the model in analyzing condition of different condition. This verification process helped to calibrate the proposed model and to make adjustments to the parameters used in the model.
Response: There is a verification of the finite element model in section 3.2 of the original paper. With the failure mode, load–slip curve, and shear bearing capacity of the specimen considered, the finite element simulation was consistent with the experimental phenomenon and results. After we read the full text, we found that the parameters of the shear connector used in the test were not given in full, which was not well considered by us. We have added them to section 2.1 using red font.
- The Finite element models for concrete and other materials require a large amount of information. The authors depended in their simulations on several perimeters that some of them obtained from past research and others assumed by the authors. Due to this lack of information, the results from the finite element models presented in the paper is a bit questionable. In general, the manuscript still requires additional revisions in the evaluation of the models presented.
Response: Thank you for this comment, which is very helpful for us to write articles in the future. We have reread the references and found that the stud diameter was also an important factor influencing the shear bearing capacity of stud shear connectors (we have added it in the introduction section in red font). Thus the stud diameter, concrete strength, opening diameter, Perforated plate thickness and Penetrating steel bar diameter were important influencing factors for the shear load capacity of stud shear connectors or PBL shear connectors, respectively. Although the laws and mechanisms of the above parameters on the shear capacity of shear connectors have been revealed, they were for PBL shear connectors or stud shear connectors. For stud-PBL composite shear connectors, the above parameters were set in one member at the same time, and the effect on the shear resistance of the member would be variable and unclear, which was valuable to study(We have added it in red font to section 4.1.).
Reviewer 2 Report
The paper is interesting and deals with and explains the issues important from the point of view of the design of composite elements. Nevertheless, Authors should clarify or describe the following issues:
- direct comparison of load-slip curves from laboratory tests and FEM analysis (on one common graph) – this will enable the assessment of their compliance,
- a more detailed description of the descending sections of the curves, necessary due to their absence in the test results – this makes it impossible to compare the graphs in this part,
- discussion of the reliability of the results obtained from the formula (6), which is based on the data taken from the FEM analysis and shows a significant discrepancy in relation to the results of model tests; it is particularly important in relation to the performance of tests for single variable parameters,
- a significant reduction in quantitative conclusions and a more comprehensive presentation of qualitative ones.
Editorial notes:
- row 137: there is Mpa, it should be MPa,
- row 137: there is m3, it should be m3,
- description in Fig. 9: there is Pu, should be Pu.
Author Response
Response to Reviewer 2 Comments
- Direct comparison of load-slip curves from laboratory tests and FEM analysis (on one common graph) – this will enable the assessment of their compliance.
Response: Your suggestion was crucial. This problem was caused by the lack of thoughtfulness when we wrote the paper before. As suggested, we have modified Figure 7. (The figure name was also revised in blue font)
- A more detailed description of the descending sections of the curves, necessary due to their absence in the test results – this makes it impossible to compare the graphs in this part.
Response: As suggested, we have revised it and marked it with blue font (Please see section 3.2.).
- Discussion of the reliability of the results obtained from the formula (6), which is based on the data taken from the FEM analysis and shows a significant discrepancy in relation to the results of model tests; it is particularly important in relation to the performance of tests for single variable parameters.
Response: We have revised as you suggested. (Revised parts have been marked in purple. Please see section 5.)
- A significant reduction in quantitative conclusions and a more comprehensive presentation of qualitative ones.
Response: We have revised the conclusion as you suggested. (Revised parts have been marked in blue.)
For Editorial notes, we have revised in the corresponding parts marked by blue font.
