A New Methodology for Determining the Friction Factor

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

 

The structure of the article is incorrect. First, the theoretical basis should be presented, then the stand used to conduct the research based on the presented theory, and finally the analysis of the results and/or comparison with previously used research methods.

The relationship between the research conducted based on the position presented in Fig. 2 and Fig. 9 is not properly defined.

The S parameter has not been defined, and lubricants have been described as groups, which is an abuse. If we want the research results to be considered representative of a given group, at least three lubricants from that group should be tested.

Figures 3 to 5 do not contribute any significant information to the article and can be combined into a single figure containing representative results for the given test conditions.

Author Response

The author's response for Reviewer 1 (round 1) is attached in a Word file.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

1. The authors should better justify in the introduction the validity of the proposed method for determining the coefficient of friction compared to the methods presented by other researchers. If possible, a more detailed description of other methods could be included in the introduction, which would make the article more accessible to readers outside the field of metal forming.

 

2. Fig. 2: Marking the direction of sample elongation will increase the clarity of the figure.

3. Figs. 3 and 4 are not very clear. The elongation of the samples is obvious. The reviewer suggests reducing or supplementing the information, e.g., providing dimensions, elongation values, etc., for example, dimension S from the following figures.

4. In the reviewer's opinion, determining the coefficient of friction is intended to be calculated (estimated) in a relatively simple manner based on the known dimensions of the material being formed and its material parameters required in the forming process (e.g., presses). In this context, please provide your conclusions on the advantages of the method proposed by the authors.

Author Response

Author's response for Reviewer 2 (round 1) is attached in Word file.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The author presents a new experimental and analytical method for obtaining the coefficient of friction. He experiments with the process using two materials, namely, C45 steel and 6026 aluminum alloy.
If you are measuring friction, then it exists between the surfaces that come into contact, of which there are four, two on top and two on the bottom. Friction is different depending on lubrication, but also on which materials are in contact. I didn't see it indicated what the material of the punch and die is.
How did you measure the deformation of the sample? The machine stroke is not acceptable because there is the flexibility of the equipment, which is certainly not zero. At the very least, you should have discounted the flexibility of the equipment from the indicated stroke, as I believe it is difficult or impossible to apply a digital image correlation system to the deforming specimen.
Figures 6 and 7. Why do they start with a load of 200-500 kN?

Author Response

Author's response for Reviewer 3 (round 1) is attached in Word file.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,
K usually denotes the Helmholtz module.
In Figures 5, 6, and 10, the word “group” appears. In the text presented, in some cases the word “type” should be written with a lowercase letter.
Although the names of sections 3 and 4 reflect the content, they do not reflect the essence of the article, which is to determine the coefficient of friction. Therefore, I suggest changing the titles.

 

Author Response

Dear Reviewer,

Please read our responses in the attached file.

Author Response File: Author Response.pdf