Analysis and Optimization of Dynamic and Static Characteristics of Machining Center Direct-Drive Turntable

Round 1

Reviewer 1 Report

The manuscript presents a multi-objective optimization approach for improving the structure of direct-drive turntable using a combination of topology optimization, neural network and genetic algorithm. 

The topic is interesting. The authors have carried out rather extensive work on the design to present the optimized solution for the structure. Their results have shown to improve the mass by approx. 20% which is very commendable. 

The authors need to improve the manuscript's presentation and grammar. Towards the end there were too many typographical error which can be avoided with careful reading. 

Following are my major concerns followed by minor issues. 

Major concerns:

1. Equation (3) and (4) are wrong. In SIMP model p is the penalization parameter which is the power on the density. It can not be a multiplication factor. 

2. Did the topology optimization results shown in Figure 7, obtained from the model shown in Figure 4 or 6?  This is not clear. Figure 7 looks more like 2D. 

3. Please put some iteration results in a Figure to show the evolution of the topology optimization. How many iterations did it take? Density based topology optimization is known to generate non-smooth boundaries. Did the authors do any post-processing? What kind of filter has been used?

4. Figures 17 to 19 are confusing? I can't differentiate between the red and the light red. What is the boundary condition of the topology optimization. The gray part make it more confusing. Are you using passive elements to keep the holes.

5. I am also a bit confused how 8 symmetrically places holes can be created by topology optimization method. Are the preselected? Also, the holes would create stress concentrations? The authors should comment on these.

Minor Issues: Please revise the manuscript for grammatical correctness, and repetetion. 

1. In line 13 include "(BP)" after Back Propagation neural network.

2.  In line 114 and line 127, the same sentence is used. 

A sketch of the structure of the direct-drive turntable is shown in Figure 1.  114

 

The structure of the direct-drive turntable is shown in the above Figure 1 :  127

3. Line 145, "This section may be divided by subheadings". Eliminate this sentence. 

4. Give a reference to "Solidworks 2020" in Line 186.

5. In line 216, Revise this sentence, "The main body of the turntable is a tetrahedral element, and the model of the work piece is a hexahedral element. 

6. In line 217, Revise, "After dividing the mesh by 10mm element size, we got 217 342,049 nodes and 174545 cell mesh after dividing mesh".  

 

7.  In 289 c was defined as structural strain energy and In 305, c was mentioned as structural flexibility. This should be consistent.

 

8. A flow chart can be constructed for clarity of the approach. 

 

9. Figure 20, the contour levels can be organized with same decimal points for clarity. 

10. Figure 22, please label with more information if possible. 

11. Figure 31, where is A. 

12. The conclusion paragraph started with lower case. 

13. Typos: The authors daclare no conflict of interest. line 819

14. Line 803, period is missing at the end of the sentence. 

 

15. Line 740. Rephrase, . It can be seen that there is little difference between the predicting value and the simulation value. The word little is subjective. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Author Response

Thanks for reviewers' comments concerning our manuscript entitled " Analysis and optimization of dynamic and static characteristics of machining center direct-drive turntable" (Manuscript ID: applsci-1909236). Those comments are all valuable and helpful for revising and improving our paper. We have studied all comments carefully and have made conscientious correction. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewers’ comments are as flowing: We tried our best to impove the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. We appreciate for reviewers’ warm work earnestly, and hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

1. When finding the limit machining position, every 10° interval is used as a loading point, whether the interval is further reduced to make the result more accurate.

2. To accurately model the dynamics of the rotary table, we want to consider the stiffness and damping of the bolt and bearing connection joints.

3. When the rotary table works, after the superposition of dynamic deformation and static deformation, if the maximum deformation position of both is the same, it will be larger than the maximum deformation requirement.

4. Literature review – this section is extensive in its coverage, but tends to summarise studies of machine tools derived from surveys. The research has seemingly overlooked the existing literature on direct-drive turntables, which is surprising given that this is the focus of the work. Furthermore, some review of optimization strategies should be given in the first part, such as Multidisciplinary design optimization of engineering systems under uncertainty: a review. 

5. The conclusion part should be more refined to make the findings and contributions of the paper clearer. Conclusions are not just about summarising the key results of the study, they should highlight the insights and the applicability of your results for further work. Furthermore, please note the difference between the conclusions and the abstract. Avoid bullet form.

6. Eliminate multiple references. This should be done by characterizing each reference individually. This can be done by mentioning 1 or 2 phrases per reference to show how it is different from the others and why it deserves mentioning.

7. Check all formats, such as 7280kg/m3 on pages 4, and 3 should be superscripted and leave a space between the value and the unit, and add a separator for numbers over 1000.

Author Response

Thanks for reviewers' comments concerning our manuscript entitled " Analysis and optimization of dynamic and static characteristics of machining center direct-drive turntable" (Manuscript ID: applsci-1909236). Those comments are all valuable and helpful for revising and improving our paper. We have studied all comments carefully and have made conscientious correction. Revised portion are marked in red in the paper. The main corrections in the paper and the responds to the reviewers’ comments are as flowing: We tried our best to impove the manuscript and made some changes in the manuscript. These changes will not influence the content and framework of the paper. We appreciate for reviewers’ warm work earnestly, and hope that the correction will meet with approval.

Once again, thank you very much for your comments and suggestions.

Please see the attachment.

Author Response File: Author Response.docx