Numerical Analysis of the Laser Forming Process of Cylindrical Surfaces

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article contains interesting numerical studies of the laser forming process for structural materials. The analysis of the computed temperature along the thickness and final effective plastic deformation results are scientifically interesting and indicate the essence of the research issue using numerical methods. Below are a few minor comments and suggestions:
1. In the introduction, please add a few sentences regarding the development of numerical methods for metal sheets over the years;
2. In the subsection 2.2, for table 1, please characterize the parameter "a" - absorption coefficient - in particular what it includes and what its scope is;
3. For table 3, please write why the energy line is expressed by the formula for the quotient, while the total energy is in the form of a product;
4. In the subsection 3.2, please add several literature items in which the defelection profile for sheets was studied using various numerical methods - so that the results constitute a form of discussion;
5. In the conclusions, please add two/three sentences regarding the numerical values ​​obtained from the research results, in particular in the field of energy line.< !--/data/user/0/com.samsung.android.app.notes/files/clipdata/clipdata_bodytext_250302_202557_752.sdocx-->

Author Response

Revised manuscript “Numerical Analysis of the Laser Forming Process of Cylindrical Surfaces”, written by Daniel Cabezas et al., submitted to Metals.

 

The authors sincerely appreciate the insightful feedback from the reviewers and have incorporated them into the updated version of the manuscript. Each of the comments made by the reviewers is responded to individually below. The changes that were made to it are shown in yellow.

 

COMMENTS FOR THE AUTHORS:

 

The article contains interesting numerical studies of the laser forming process for structural materials. The analysis of the computed temperature along the thickness and final effective plastic deformation results are scientifically interesting and indicate the essence of the research issue using numerical methods. Below are a few minor comments and suggestions:

 

1. In the introduction, please add a few sentences regarding the development of numerical methods for metal sheets over the years;

Answer: Sentences were added to highlight the evolution and impact of numerical methods in sheet metal forming, emphasizing their importance in predicting material behavior and optimizing manufacturing processes.

 

2. In the subsection 2.2, for table 1, please characterize the parameter "a" - absorption coefficient - in particular what it includes and what its scope is;

Answer: The absorption coefficient explicitly quantifies the percentage of the heat flux provided by the laser beam that actually enters the irradiated sheet material. This comment was included in Box 1.

 

3. For table 3, please write why the energy line is expressed by the formula for the quotient, while the total energy is in the form of a product;

Answer: The energy line ( = ) is expressed as a quotient because it represents the energy applied per unit length, depending on the laser power () and scanning speed (). In contrast, the total energy (= ) is a product because it accumulates the energy over multiple passes (), reflecting the cumulative heat effect on the material. The total energy could have been written also as: .

 

4. In the subsection 3.2, please add several literature items in which the deflection profile for sheets was studied using various numerical methods - so that the results constitute a form of discussion;

Answer: In subsection 3.2, we have added references that analyze the deflection profile of sheets using artificial neural network (ANN) models and the finite element method (FEM). These additions strengthen the discussion on the accuracy and advantages of FEM in laser bending simulation.

 

5. In the conclusions, please add two/three sentences regarding the numerical values ​​obtained from the research results, in particular in the field of energy line.

Answer: Sentences were added to detail the numerical values obtained in the research, with a particular focus on line energy and its influence on material behavior during the process.

 

General comment: Introduction and Conclusions were improved.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This paper provides a newly developed numerical model to simulate the laser forming process. The topic is worthy to investigate and the proposed numerical model has its own value for the efficient calculation of the results of the laser forming process. 

However, currently in overall the paper describes the main results without discussions. In the reviewer's opinion, an in-depth discussions are needed to publish this paper in a scientific journal such as MDPI Metals. Adding detailed temperature evolutions during the laser scanning with different processing parameters and relevant discussions about the laser bending mechanism seem to be essential for this paper.  

Author Response

Revised manuscript “Numerical Analysis of the Laser Forming Process of Cylindrical Surfaces”, written by Daniel Cabezas et al., submitted to Metals.

 

The authors sincerely appreciate the insightful feedback from the reviewers and have incorporated them into the updated version of the manuscript. Each of the comments made by the reviewers is responded to individually below. The changes that were made to it are shown in magenta.

 

COMMENTS FOR THE AUTHORS:

 

This paper provides a newly developed numerical model to simulate the laser forming process. The topic is worthy to investigate and the proposed numerical model has its own value for the efficient calculation of the results of the laser forming process.

 

However, currently in overall the paper describes the main results without discussions. In the reviewer's opinion, an in-depth discussions are needed to publish this paper in a scientific journal such as MDPI Metals. Adding detailed temperature evolutions during the laser scanning with different processing parameters and relevant discussions about the laser bending mechanism seem to be essential for this paper. 

Answer: In Subsection 3.2, elements were added regarding relevant discussions on the laser bending mechanism and showing other studies. Graphs showing temperature evolution were incorporated, and the relationship between the thermal build-up effect on the plate during irradiation was established.

 

General comment: Results and Conclusions were improved with further arguments and discussions.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

This paper presents a numerical simulation study of the multi-pass laser forming (LBF) process used to produce cylindrical surfaces from flat AISI 304 stainless steel plates. The study explores the influence of key process parameters—laser power, scanning speed, and distance between irradiation lines—on resulting curvature, temperature distribution, and plastic deformation. Some comments can be found as follows:

1. The abstract clearly summarizes the study but would benefit from including specific numerical findings
2. Consider briefly stating the application or industrial relevance of cylindrical laser-formed parts.
3. Extend the literature review to provide a clear novelty of this work
4. Consider defining the practical challenges in cylindrical LBF, such as repeatability, precision, and process control, earlier in the introduction.
5. It would be helpful to explain why phase transformations and strain rate effects were neglected; even a brief sensitivity justification would support this assumption.
6. Experimental tests must be described in more details
7. Improve the numerical part and explaining what kind of software is used to perform the simulation
8. Conclusion can be improved and extended as well to show the main benefit and the points achieved in this paper

Comments on the Quality of English Language

English can be revised and improved

Author Response

Revised manuscript “Numerical Analysis of the Laser Forming Process of Cylindrical Surfaces”, written by Daniel Cabezas et al., submitted to Metals.

 

The authors sincerely appreciate the insightful feedback from the reviewers and have incorporated them into the updated version of the manuscript. Each of the comments made by the reviewers is responded to individually below. The changes that were made to it are shown in green.

 

COMMENTS FOR THE AUTHORS:

 

This paper presents a numerical simulation study of the multi-pass laser forming (LBF) process used to produce cylindrical surfaces from flat AISI 304 stainless steel plates. The study explores the influence of key process parameters—laser power, scanning speed, and distance between irradiation lines—on resulting curvature, temperature distribution, and plastic deformation. Some comments can be found as follows:

 

1. The abstract clearly summarizes the study but would benefit from including specific numerical findings

Answer: The summary of the document was improved by incorporating the main results of the numerical modeling, highlighting the influence of the parameters on temperature and deformation. In particular, the impact of the distance between irradiation lines is emphasized due to its relevance in the formation of curved surfaces.

 

2. Consider briefly stating the application or industrial relevanceof cylindrical laser-formed parts.

Answer: The relevance of curved laser bending in different industrial sectors was highlighted.

 

3. Extend the literature review to provide a clear novelty of this work.

Answer: The literature review was expanded to include new elements on the importance and difficulties of the laser process for forming cylindrical surfaces, as well as references to other studies on the shaping of complex surfaces using lasers.

 

4. Consider defining the practical challengesin cylindrical LBF, such as repeatability, precision, and process control, earlier in the introduction.

Answer: The main challenges of laser bending were highlighted, including the correct selection of heating parameters and the precise definition of irradiation lines, which are key aspects of the process.

 

5. It would be helpful to explain why phase transformations and strain rate effectswere neglected; even a brief sensitivity justification would support this assumption.

Answer: no phase transformations are taken into account in the analysis since they are widely recognized to not play a significant role in the thermomechanical response of the sheet during the laser beam irradiation. This assumption was justified by referencing an example from the literature where they were also neglected, thereby supporting the validity of our approach.

 

6. Experimental tests must be described in more details

Answer: All the details provided by the author of the reference article regarding the experimental tests were added.

 

7. Improve the numerical part and explaining what kind of software is used to perform the simulation.

Answer: The thermomechanical formulation presented in the manuscript was solved in the context of the finite element method via an in-house widely validated by the authors in different LBF applications (see references cited in Subsection 2.2).

 

8. Conclusion can be improved and extended as well to show the main benefit and the points achieved in this paper

Answer: The conclusions were expanded by adding elements related to the numerical results obtained in the research, specifically regarding line energy and the distance between irradiation lines.

 

Aspects that have been improved:

The use of English language, background of the Introduction including all relevant references, research design, description of the methods used, presentation of the results and conclusions supported by the obtained results.

 

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is improved and I would like to recommend this paper to be accepted.

Reviewer 3 Report

Comments and Suggestions for Authors

Ok