Response Characteristics of Harvester Bolts and the Establishment of the Strongest Response Structure’s Kinetic Model

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors and editors, I will use the MDPI reviewer's suggestions format to evaluate and review this research work, as can be observed below. Please, carefully respond to each of the following comments that can be found within each question.

1. What is the main question addressed by the research?

This paper analyzes an agricultural harvesting machine working in the field in the context of the bolts and connections' vibration direction and the most complex vibration parts of bolts and connections. The authors performed vibration response experiments to analyze the time-domain and frequency-domain signals. This paper's findings can help to reduce the failure of bolted connections in rice combine harvesters.

2. What parts do you consider original or relevant for the field? What specific gap in the field does the paper address?

The vibration response experiments to analyze the time-domain and frequency-domain signals in agricultural harvesting machines working in the field are interesting.

3. What does it add to the subject area compared with other published material?

Earlier research has created large-scale dynamics models and micro-dynamics features of bolt systems, which were used to make dynamic models to study how they respond. Some papers have also examined why bolts fail and devise ways to improve things using these models. One thing that hasn't been looked into enough is how the main bolt connection structures react to the general multiple excitation of a harvester. This work proposes interesting insights related to this topic that have not been reviewed earlier.

4. What specific improvements should the authors consider regarding the methodology? What further controls should be considered?

In general, the paper demonstrates a low level of writing and organization. However, the article effectively addresses the challenges of the bolt time-domain and frequency-domain signal analysis problem. A few recommendations to improve the paper's quality can be found below.

- Please, improve writing and correct grammar errors. This would help in understanding the paper. 

- Please, improve the state of the art and the introduction of this paper.

- Please, improve the writing of the abstract. It is hard to understand what is the paper about by reading only the abstract.

- There is in Figure 38.d a Chinese language text within it. Please, correct that.

- Please, provide a figure of the proposed architecture to perform the experiments. You can use a block diagram combined with images to create the figure. Each part of such architecture should be a section of the materials and methods section.

- I strongly recommend adding a discussion section with all the main findings of the article.

- In the discussion section, please, comment if it is possible to analyze the bolt materials efforts using specialized software such as Solid Works, Autodesk Inventor, and Abaqus, among others. 

- Section "3.4. The establishment method of theoretical model under macroscopic dynamics" is within the results section. Please, the results only should show results. We also suggest to separate the results section from the discussion section.

- Please, improve all the article structure, and check for writing errors.

5. Please describe how the conclusions are or are not consistent with the evidence and arguments presented. Please also indicate if all main questions posed were addressed and by which specific experiments.

The article's conclusions are consistent and have evidence to support the author's arguments.

6. Are the references appropriate?

The references are updated and consider mostly articles from the last 5 years. Moreover, the references match this work topic.

7. Please include any additional comments on the tables and figures and the quality of the data.

It is recommended to move figures 40 and 41, and all the sections related to it to the materials and methods section. Currently, they are in the results section.

 

 

Comments on the Quality of English Language

Extensive editing of the English language is required.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The article describes topics that are important in the construction and operation of machines. When designing new machine structures or changing existing structures, designers should have enough data from scientific experiments to ensure that the new work units they propose are free from defects.

The authors of the article rightly focus on loads caused by vibrations. This topic is complicated due to the large number of places where these vibrations arise, especially in an agricultural machine such as a combine harvester, which is equipped with many working units.

The article correctly describes the experiment and shows the results clearly enough. The presented work has a good scientific sound.

the authors described in detail the scope of the planned work
the authors correctly described the experiment being carried out (collecting data from sensors)
data presented in the form of tables and charts are easy to read and do not require correction,
the presented mathematical and theoretical model correctly refers to the physical phenomena occurring in the operating conditions of the machine
the distribution of forces was correctly presented in the analyzed bolted connections.
In further work, the following should be taken into account and described:
How does the material of the connectors (screws) affect the results of the experiment and the mathematical model? Has this problem been analyzed?
How can the test results be related to different types of threads?
Which threaded connections were analyzed?
Have the initial stresses introduced in the threaded connections been taken into account?
Were the screws new or used before?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Title: Response Characteristics of Harvester Bolts and Establishment of Strongest Response Structure’s Kinetic model

My comments:

Analysis of the article was difficult without line numbers.

Please, line numbers should be added.

 The chapters with difficulties are Introduction, Material and Methods, Discussion and Conclusions.

My comments:

Title: Response Characteristics of Harvester Bolts and Establishment of Strongest Response Structure’s Kinetic model. OK

 

Abstract:

Abstract must be corrected.

In the abstract should state briefly the purpose of the research, the principal results and major conclusions.
What is the purpose of the article?

 

Keywords: I don't think that it is correct to repeats in the keywords the same words that are in that title and Abstract.

Keywords, Search engines search Title and Abstract. Hence, include only words or terms that do not appear in the title or Abstract. e.g. Bolt: harvester; Kinetic model.

 

Introduction:

In the introduction chapter, the links between the different statements should be reinforced.

For example: What are the objectives of the paper?. This should be rewritten more appropriately.

I repeat: Analysis of the article was difficult without line numbers.

 

In the following paragraphs (page 2), the authors do not clearly express the objectives of this work.

“At the same time, some studies analyzed and optimized the failure situation of bolts according to the dynamic model of machinery, and put for-ward the optimization scheme of machinery. However, it is rare to analyze the response characteristics of the main bolt connection structures under the overall multiple excitation of the harvester, and to model the dynamics of the overall bolting connection structure of the harvester.

The bolts and connections of the rice combine harvester are research objects in this paper, and the main vibration direction and the most complex and strong parts of the connecting bolts and connecting parts in the time variable multi load excitation system were obtained though the vibration response experiment. And then, The response characteristics in different orientations of each device were obtained though the analysis of signals in time domain characteristics and frequency domain characteristics. The most obvious response was the bolts on the vibrating screen through comparative analysis and the multiple degrees of freedom centralized mass dynamics model of the bolts was established based on the analysis of static mechanics and failure mode. On the one hand, combined with the vibration response experiment of bolt connection structures of the combine harvester, the connections and bolts of the most responsive structures were obtained. On the other hand, the macroscopic kinetic model was established and model of the tangential response of the microscopic contact surfaces was optimized through load analysis. The analytic method of response characteristic and the establishment method of the kinetic model and the microscopic response model of the structures of intense vibration response provided the mathematical model basis for the combine harvester”.

The above paragraphs (see end of page 2), in my opinion, does not express the objective or purpose of the work. It looks like a paragraph from the "methods" chapter.
The introduction of a scientific paper should not end this way. This also implies a rewritten it.

 

Methods and Materials:

A confusing description of methods and methodology is a weak point of manuscript. Incorporation of additional information on methods and methodology is necessary. This chapter needs also a rearrangement of text. The section method contains part of introduction and results.

Also, it is not clear the experimental design.

 

For example, the next two paragraphs aren’t a method. 

 “The frequency structure of combine structure is mainly concentrated in the low frequency band, Even the frequency transfer of multiple should be medium and low fre-quency. The noise signal generated by the bolt failure during the operation stage is a high-frequency signal component, so”… (see page 3).

 

2.4. The analysis of critical relative slip displacement under static load (see page 7).

Thread pair is a kinematic pair composed of the rotation of internal and external threads. The sliding displacement of bolt thread pair and the accepted simplified model (the slope slider model) are shown in Figure 7. If horizontal external load is smaller, it is not enough to cause the bending of the bolt rod and does not slide the moving plate against the setting plate. The bolt rod gradually bends the deformation with the increas-ing transverse load and the bolt rod was simplified to a cantilever. If F0 > Ff2, there is small sliding displacement between fixed plate and the moving plate. So there is not sliding displacement between fixed plate and the bolt head but the bolt rod has initially bent. If F0 > Ff2(F0 > Ff3), the whole structure of the bolt enters the structural loosening period and the bolt rod is fully bent.

In the above paragraph, the authors are doing an analysis of the slip under a certain load.

This is a result. It is not a material and methods.

Situations like this are repeated throughout the entire chapter.

 

Results and Discussion

The results are correctly presented. The problem of this chapter is the discussion of results. In any case, I consider that the authors should discuss their results in comparison with other papers.

In the Introduction chapter, 25 papers were cited, but none were discussed.

In summary, the way this chapter is written, I believe that there is no discussion of results.

Please rewrite.

I believe that the results chapter should be separated from the discussion chapter.

 

 

Conclusions

 

1) Based on the excitation response experiment of connection structure of combine harvester and the analysis of response signals under time domain characteristic, the response characteristics of bolt connections were analyzed (see page 28).

 

The above paragraph isn’t conclusion. The authors are saying what they did. This was already explained in the methodology, it is not a conclusion. This must be deleted.

 

The vibration energy intensity in the 4 Z direction is mainly concentrated at 12.42 m/s2 with the peak vibration of 109 m/s2~115.68 m/s2.

 

The above lines aren’t conclusions. (See the following lines). They are written on page 17 in the Results and Discussion chapter.

 

The vibration accelerations of 4-Z direction are main concentrated at 12.42 m/s2 and the peak value of vibra-tion is 109 m/s2~115.68 m/s2. (See page 17)

 

 

(2) Based on the excitation response experiment of connection structure of combine harvester and the analysis of response signals under frequency-domain characteristic, the response characteristics of bolt connections further were analyzed. (See page 28).

The above paragraph isn’t conclusion. The authors are saying what they did. This was already explained in the methodology, it is not a conclusion. This must be deleted.

 

 

 

 

Different from other measuring points, the main frequency at 4 Z direction is 2.32 Hz(The reciprocating motion frequency of vibrating screen), the another value point is at the position of the 16 times the frequency (37.0794 Hz) of reciprocating motion frequency of the vibrating screen.

 

The above paragraph isn’t conclusion. (See the following paragraph). This paragraph was written on page 24 in the Results and Discussion chapter (see page 24).

 

The main frequency at 4-Z is 2.32 Hz (The frequency of Reciprocating motion of the vibrating screen), which is different from the other measure points. The another amplitude point is 16 times the frequency of the vibrating screen with reciprocating motion of 37.0794 Hz (see page 24).

 It is not correct to repeat the results in the conclusions. The conclusions must be rewritten.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have responded to the comments made in the previous review successfully. In particular, improvements have been made in the following points:

- The introduction and methodology writing has been improved and revised, taking into account all the recommendations made.

- The proposed methodology used for this application has been reviewed and is better explained.

- The quality of the figures, and their explanation has improved significantly.

- Fixed writing errors in the article.

-The authors improved the discussion of the results, and the contribution of the article is explained in a better way.

Based on this, I can say that this paper can be published in its current state.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors:

This manuscript shows a substantial improvement. Therefore, it fits perfectly well within the scope of the journal.

Authors took all my comments into account and performed several changes in the text representing a clear improvement from the previous version.

Therefore, I have no more to add.

Best reagards.