Failure Life Prediction of Hub Bearing in Composite Tooling

Round 1

Reviewer 1 Report

Dear authors,
research and tests are very interesting and certainly required a lot of work.

However, I have a few comments:
1) few references to literature and other articles,

2) Why didn't you compare the results of non-composite rolling bearings with "normal" rolling bearing?
3) Lack of technical data for the composite rolling bearing

4) Please correct the description of figure 4. What happened above 160 to 215 seconds of the test?

5) In the description of the problem of rolling bearings testing, there should be information about testing of rolling bearings by vibroacoustic methods. I recommend doing the test using this method.

6) in the summary of point 5 (noise) - the text has no results regarding noise. The only information at work is how long after the disturbing noise occurred. What were the noise measurements made? Please provide a noise graph as a function of time.

Best regards and a lot of health in that epidemic time

Author Response

Reviewer#1: Comments and Suggestions for Authors

 

Dear authors,

research and tests are very interesting and certainly required a lot of work.

 

However, I have a few comments:

1) few references to literature and other articles,

→ Some references have been added according to the reviewer's opinion.

 

2) Why didn't you compare the results of non-composite rolling bearings with "normal" rolling bearing?

→ The purpose of this paper is to analytically predict the fatigue life of the hub bearing used in composite working implements in Figures 1 and 2 and validate it under the test. Therefore, I did not compare the study results of the hub bearing with other bearings, and I do not think that it is necessary to compare them. In many bearing papers mentioned in the references, there is no case in which the results of studies on bearings are compared with other bearings.

 

3) Lack of technical data for the composite rolling bearing

→ I think that the reviewer mistook the hub bearing for being made of composite material. In this paper, the hub bearing is an ordinary bearing made of steels, not a composite bearing. The composite tooling and composite working implements mentioned in the paper refer to 'a machine that can simultaneously perform multiple tasks' and have nothing to do with a composite bearing. Therefore, there was no need to present technical data on composite bearings.

 

4) Please correct the description of figure 4. What happened above 160 to 215 seconds of the test?

→ Figure 4 shows the test results when the speed of the tractor was 14 to 16 km/h and the plowing depth was 20 to 30 cm, and the field test results from 1^st to 5^th were concatenated and displayed as one graph. Here, the reason that the strain value at the 4^th field test was relatively larger than the other test data is considered to be due to the influence of change of soil composition and plowing depth even in the same test field. So, I have corrected Figure 4.

 

5) In the description of the problem of rolling bearings testing, there should be information about testing of rolling bearings by vibroacoustic methods. I recommend doing the test using this method.

→ The life test of the bearing was conducted to evaluate the bearing fatigue life. The abnormal noise and vibration mentioned in this paragraph is not the result of measurement using a sensor, but the noise and vibration perceived through the human ear and tactile sense during the bearing life test. Additionally, noise and vibration tests have not been performed by vibroacoustic methods. The content of the manuscript was corrected.

 

6) in the summary of point 5 (noise) - the text has no results regarding noise. The only information at work is how long after the disturbing noise occurred. What were the noise measurements made? Please provide a noise graph as a function of time.

→ The life test of the bearing was conducted to evaluate the bearing fatigue life. The abnormal noise and vibration mentioned in this paragraph is not the result of measurement using a sensor, but the noise and vibration perceived through the human ear and tactile sense during the bearing life test. The content of the manuscript was corrected.

Best regards and a lot of health in that epidemic time

Author Response File: Author Response.docx

Reviewer 2 Report

Equation (1) is illeglible, especially the content of the bracket. It needs to be corrected.

Description of the axes in Figures 12-15 shall be enlarged because they are illegible.

There is no explanation why the authors used the Weibull distribution. In addition, reliability should not be expressed in%, because it is a function that takes values from 0 to 1. The reviewer recommends improving this record in all workplaces.

Author Response

Reviewer#2: Comments and Suggestions for Authors

 

1) Equation (1) is illeglible, especially the content of the bracket. It needs to be corrected.

→ The equation has been corrected according to the reviewer's opinion.

 

2) Description of the axes in Figures 12-15 shall be enlarged because they are illegible.

→ The figures have been corrected according to the reviewer's opinion.

 

3) There is no explanation why the authors used the Weibull distribution. In addition, reliability should not be expressed in%, because it is a function that takes values from 0 to 1. The reviewer recommends improving this record in all workplaces.

→ I think that there is no need to explain the theory that the bearing life follows the Weibull distribution. That is because the theory was already released in the 1950s and so well-known. Other papers related to bearing life were applied the theory without further explanation. ISO 281 in reference 10 is a bearing life prediction formula based on the theory. So I used it without a separate explanation.

Additional content has been corrected according to the reviewer's opinion.

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript is not well written and organized. The introduction must be reviewed. The experimental methodology used is not explained appropriately. I still have some questions; the answers will increase the level of the paper.

See attached file.

Comments for author File: Comments.pdf

Author Response

Reviewer#3: Comments and Suggestions for Authors

 

The manuscript is not well written and organized. The introduction must be reviewed. The experimental methodology used is not explained appropriately. I still have some questions; the answers will increase the level of the paper.

 

See attached file: peer-review-7564789.v2.pdf

 

Review report:

Journal: Applied Sciences (ISSN 2076-3417))

Manuscript ID: applsci-833422

Title: Failure Life Prediction of Hub Bearing in Composite Tooling

Summary:

The paper was conducted to predict the fatigue life of the hub bearing used in composite working implements. The composite working implement in the study is one that simultaneously performs tillage operation and hilling work. The load acting on the composite working implement was measured through field tests, and the combined loads acting on the hub bearing were derived using the load reconstruction method. Based on the derived loads, the static safety factor, and fatigue life of the bearing, the load acting on the inner and outer raceways of the bearing, contact stress, and truncation were analytically predicted. Besides, the predicted fatigue life of the bearing was verified through a life test.

Comments:

The manuscript is not well written and organized. The introduction must be reviewed. The experimental methodology used is not explained appropriately. I still have some questions; the answers will increase the level of the paper:

 

1. Introduction must provide a comprehensive critical review of recent developments in a specific area or theme. Introduction is expected to have an extensive literature review followed by an in-depth and critical analysis of the state of the art. Bibliographic references must be explained individually and not grouped. In this section it would be opportune to introduce the experimental methodology that will be used in the manuscript with respect to the mentioned bibliographic references. Describe how the results will be presented. I suggest adding information to better describe what other researchers have done in this area.

→ The introduction has been corrected according to the reviewer's opinion.

 

2. In the introduction the bibliography does not seem to be quite recent, only 8 works on 25 mentioned are of the last five years. It would be appropriate to cite the more recent works. Bibliographic references must be explained individually and not grouped.

→ Some references of the last five years have been added according to the reviewer's opinion, and the description of the added references has been added to the introduction.

 

3. It is not clear if the results shown in figure 4 refer to the 8 tests carried out, and therefore the average of the eight tests is plotted or what? Explain this point better. The same occurs for the fig. 6 and 7.

→ Figure 4 shows the test results when the speed of the tractor was 14 to 16 km/h and the plowing depth was 20 to 30 cm, and the field test results from 1^st to 5^th were concatenated and displayed as one graph. Here, the reason that the strain value at the 4^th field test was relatively larger than the other test data is considered to be due to the influence of change of soil composition and plowing depth even in the same test field. So, I have corrected Figure 4, 6 and 7.

 

4. In the figure 5 it is not clear the positions of the axes. Does the z-axis have an angle of 20° from the Y-axis? The figure is unclear. Indicate better the axes in the text.

→ The figure 5 has been corrected according to the reviewer's opinion.

 

5. In the figure 8 the position of the axes is not clear. Please check that in the whole manuscript, ad explain the axes positions.

→ The figure 8 has been corrected according to the reviewer's opinion.

 

6. When the Authors, in page 7, lines 78-79, talk about: “The equivalent load was split into loads in the x, y, and z directions using the angle of the principal direction of the disk harrow assembly” what is this angle?

→ The description of angle has been added according to the reviewer's opinion.

 

7. When the Authors, in page 9, lines 225-226, talk about: “The maximum contact stress levels were shown to be 2230 MPa and 2171 MPa …”, from the analysis of the figures these values are not read for various reasons:

• the font size, legends and axes are too small and illegible,
• the quality of the images is poor, improve the images.
• The MPa values in the figures are 230.0 MPa, 240.0 MPa and not 2300 MPa.

The same occurs for the figures 14 and 15.

→ The figures 12-15 has been corrected according to the reviewer's opinion.

 

8. The bibliographic references used to explain the research methodology is totally absent. Other studies by other authors should also be indicated to confirm the robustness of the methodology adopted.

→ The references to research methodology has been presented according to the reviewer's opinion.

 

9. The results presented cannot have any scientific relevance because their variability is lacking. Furthermore, there is no comparison, even minimal, with other results in the scientific literature.

→ The purpose of this paper is to analytically predict the fatigue life of the hub bearing used in composite working implements in Figures 1 and 2 and compare the predicted result with the test result. Therefore, I did not compare the study results of the hub bearing with other bearings, and I do not think that it is necessary to compare them. In many bearing papers mentioned in the references, there is no case in which the results of studies on bearings are compared with other bearings or other research result.

 

10. As for the introduction section, the conclusions seem more a discussion of the results than of the real conclusions. The conclusions highlighting the reasons for the research, summarizing the steps followed for the development of the results and highlighting the results obtained. Rewrite the conclusions.

→ The conclusion has been corrected according to the reviewer's opinion.

 

 

For all the regions previously exposed, I consider that the article needs major revision before its publications.

 

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors have completely organized and structured the article. The manuscript has been considerably improved with the addition of suitable bibliographic references with the research presented. The manuscript is now well organized and well written. For this I suggest to accept the manuscript in present form for its publication.