Practical Approaches for Acoustic Emission Attenuation Modelling to Enable the Process Monitoring of CFRP Machining

Round 1

Reviewer 1 Report

In monitoring the Milling Process with AE sensors, I was interested in your approach to reconstruct the attenuation, dispersion, and reflected frequency spectra by obtaining the transfer function in advance for each relative position between the processing and observation locations.

Please consider revising the paper with respect to the following points: 

1.  Regarding the thesis structure, only section 3.1 exists in chapter 3, which is considered an inappropriate structure.

Please choose whether Chapter 3 should be composed of two sections, or whether each verification should be described in a separate chapter. 

2. There are several typos in the text. Please check the spelling.　　(Page10 Line317, Page9 Line287 "normalised" , etc.)

Author Response

The authors thank the reviewer1 for his/her helpful comments.

1) Section 3.1 was changed to section 4.

2) The text is supposed to be written in british english, so "normalised" is correct, same goes for "fibre", "analysed", "parameterised", "centimetre", "aluminium" and "minimised". 
Checked all terms and seems to be correct in BE.

Kind Regards

Reviewer 2 Report

The paper presents a practical approaches for AE attenuation modelling to process monitoring of CFRP machining. In-depth theoretical analysis and experimental verification are carried out in this paper. The study is well-described and experimental results are nicely demonstrated. The current paper is worthy of investigation and organization. The following comments need to be addressed to be accepted for publication.

1. The structure of the manuscript should be optimized. The conclusion section should be in the last part. In section 3, only section 3.1 is incuded. 

2.  In Figure 1 b),  the content of the 8 pictures needs to be explained.

3. In Figure 2, I'm confused about the attenuation part of the diagram.

4. It is suggested that Figure 3 presents a photograph of the experimental system.

5. The experimental  parameters should be given in Figure 9 and Figure 12.

6. The discussion section needs to be more detailed. 

7. What is the purpose of process monitoring? Experiments need to be carried out considering the monitoring target to verify the accuracy of the modeling.

8. It is suggested to consider the influence of cutting tools on AE signal.

Author Response

The authors thank the reviewer2 for his/her helpful comments.

1) Section 3.1 is now section 4.

2) More labeling has been added in Figure1b for clarification.

3) Attenuation in Figure2 has been further explained in the text for clarification.

4) Unfortunately, a photograph does not add to clarification and would rather add more confusion. Schematic is left as is.

5) Experimental parameters have been added in Figure 9 and Figure 12.

6) Discussion section has been improved for clarification.

7) As explained in the Introduction, main purpose of process monitoring is indirect measurement of tool wear as well as detection of workpiece damages and tool breakage.
Scope of this paper are the attenuation/ dispersion and methods for reconstructing AE frequency spectra in CFRP for industrial milling operations. 
The accuracy of the modelling is shown in the paper for generic spectra, the investigation of accuracy of the 
modelling for the specific process monitoring tasks is scope of further research.

8) In this paper, models have been proposed which identify the effects of attenuation/dispersion on AE in CFRP can be employed independently for different cutting tool geometries. 
As stated in 7), investigation of different tooling is scope of further research.

Round 2

Reviewer 2 Report

The manuscript has been effectively revised. I am recommending this manuscript for publication.

I suggest that Figure 3 shows the experiment system using a combination of photograph and schematics.

Author Response

The authors thank the reviewer for his/her valuable input.

A photograph has been added in Figure3.