Dynamic Cutting Force Prediction Model and Experimental Investigation of Ultrasonic Vibration-Assisted Sawing

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper investigates ultrasonic vibration–assisted metal band sawing (Ultrasonic Vibration–Assisted Band Sawing), aiming to address the challenges encountered in conventional band sawing, including large cutting force fluctuations, poor force predictability, low sawing efficiency, and severe workpiece surface washboarding. A dynamic cutting force prediction model is proposed by integrating the string vibration theory of the saw blade with a variable cutting-depth mechanism, and systematic experimental validation is carried out. However, the manuscript still contains the following issues that require revision.

(1) The rationality of the modeling assumptions requires further clarification. It is recommended that the key assumptions be explicitly listed at the beginning of the modeling section, along with a brief explanation of their applicability range and potential influence on prediction accuracy.

(2) The manuscript states that the vibration response at the center of the cutting zone is identical for different excitation locations (upstream and downstream); however, the physical explanation for this observation is relatively brief.

(3) Some figures in the manuscript are not sufficiently clear, such as Figures 3 and 4; please ensure that all figures throughout the manuscript are presented with adequate clarity and resolution.

(4) In Section 2, the derivation of the interference and overlapping cross-sectional area between adjacent teeth involves a large number of equations, which adversely affects the overall readability of the manuscript.

(5) The description of the cutting force error evaluation metric is somewhat confusing, as both positive and negative error values are reported in the table, while the error definition is based on absolute values, which may lead to ambiguity in interpretation.

(6) The engineering background for the selection of experimental parameters could be further clarified, for example, the reasons for choosing 304 stainless steel, a sawing speed of 34 m/min, and a preload range of 0.1–0.5 mm.

(7) There is still room for improvement in the consistency of language and notation, as some symbols are repeated, subscripts are not used uniformly, and certain English expressions are overly verbose.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper investigates the ultrasonic vibration-assisted band sawing using theoretical modeling with experimental validation. The authors attempt to overcome the cutting force fluctuation and surface defects in conventional sawing by a vibration-assisted method. However, many phenomena (as shown in the following comments) are not well explained, which makes the findings and conclusions confusing and unreasonable. The reviewer recommends that a major revision needs to be done, and the following issues should be addressed.

 

1. In abstract, the authors mention that ultrasonic vibration-assisted sawing reduces the average cutting force by about 15% and the feed force by about 18%. It also makes the surface roughness better by about 21%. Are these improvements the same in all tested conditions, or do they only happen with certain combinations of parameters? Please clearly define the applicable range for the realization of these benefits.

 

2. The single-tooth cutting force model in Section 2.1 uses a dimensionless proportional coefficient (λ). How was this coefficient determined or estimated? Is it constant, or does it vary with cutting conditions?

 

3. The string vibration model (Section 2.2) is based on the idea that the boundary condition is simply supported. How realistic is this assumption, given how complicated it is to mount and tension a band saw blade in real life? Have you thought about or tested the boundary conditions experimentally?

 

4. The variable-depth cutting model includes an “adjacent-tooth overlap effect”. Could you give more information or a diagram that shows how this overlap is measured, especially for teeth that are skewed? The current derivation is very mathematical, which may make it hard to understand what it means in the real world.

 

5. In the experimental setup (Section 3.1), a T3/4 M42 blade with variable-pitch teeth is used. How does this complicated tooth shape affect how well your model works, since it assumes that all teeth are in the same shape?

 

6. The ultrasonic excitation is applied 65 mm away from the center of the workpiece. Was this location optimized? How sensitive is the cutting force response to the position of the excitation?

 

7. Figure 19 shows how the measured cutting forces differ from what was expected. Even though the trends are the same, the phases are different, and the amplitudes are different. What could be causing these differences?

 

8. Table 8 was wrongly labeled as Table 9. Please check whether the labels “Preload” and “Feed rate” are reversed in Table 8.

 

9. The average dynamic cutting force error rate is 5.44%, but Table 8 shows that some error rates are as low as 0.38% and as high as 42.3%. What makes these mistakes so big (like 42.3%)? Is the model not as accurate when the feed rates or preloads are higher?

 

10. The authors think that “intermittent cutting” and “suppression of random vibrations” are reasons caused the force to decrease. Can you give a more in-depth physical explanation of how ultrasonic vibration changes the way 304 stainless steel chips form, how tools touch workpieces, and how plasticity works?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The author has made great efforts to improve this article. I think the current version is suitable for publication.