Review Reports - Determination of the Bending and Shear Properties of Wood-Based Materials Using the TIMOSHENKO Beam Theory

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Overall Assessment

The study presents a method for determining both the bending and shear properties of wood veneer composites (WVC) using a three-point bending test. This approach enables the evaluation of bending and shear modulus values through an analytical model based on Timoshenko beam theory, by conducting tests with different span-to-height ratios.

The testing and analytical procedures employed in this study were grounded in recognized standards, which were explicitly defined to ensure methodological validity and repeatability. Furthermore, the results were presented within a coherent framework relevant to the WVC industry, demonstrating that the study was methodologically sound and rigorously designed.

The specific gap in the existing literature that this study intends to address is not clearly defined, and the research objective has not been explicitly stated. The authors are encouraged to clarify the novelty of the work and to articulate the aim of the study more explicitly in order to strengthen the overall contribution.

Line 99: The manufacturing parameters of the commercial birch plywood used as material (e.g., type of adhesive) have not been reported. The authors are encouraged to provide these details, as they are essential for ensuring reproducibility and for allowing a more comprehensive evaluation of the results.

Line 168: It would be beneficial to discuss the obtained global elasticity modulus results of birch plywood in comparison with previously reported elasticity modulus values in the literature. Such a comparison would provide a clearer context for the results and strengthen the discussion.

Line 206: It would be more appropriate to discuss the obtained bending and shear strength results of birch plywood by comparing them with previously reported bending and shear strength values in the literature.

Line 268: It is recommended that statistical analysis be applied to “Table A2: Results of the material tests,” as this would provide a clearer understanding of whether significant differences exist between the groups and strengthen the interpretation of the results.

Line 336: Please recheck it in accordance with the Manuscript Preparation of References guidelines.

Comments for author File: Comments.pdf

Author Response

Thank you for your review. I have revised the manuscript and incorporated your comments. Information about your comments can be found below the text. I have also enlarged the images of the key figure graphs.

Comment: I've included manufacturing parameters specified by the manufacturer, as well as information about any existing material defects. I've deliberately refrained from mentioning the manufacturer.

Comment: I have made a comparison with selected sources

Comment: In my opinion, a statistical analysis is not useful for the main conclusions of this article. In my opinion, it would significantly increase the scope of the work, but the significance would be only slightly reduced. A difference is obvious in the global Young's moduli. You are right about defining a "universal" flexural strength for all tested configurations and span-to-height ratios. This would be necessary for this. Therefore, I have deleted the sentence in the "Results - Stresses" section about a flexural strength for all configurations. I will consider this for future research, including a statistical analysis.

Line 336: Please recheck it in accordance with the Manuscript Preparation of References guidelines.

Comment: I corrected it.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

thank you for choosing the topic of Timoshenko beam theory in characterization of plywood bending. In my opinion, introduction is written well. I read the aim of your submission as utilization of low span to height ratio plywood specimens to characterize their bending. Basically, you have not risen any objection to validity of 16 to 20 values in current standard. The troubles started with characterization of commercially available birch plywood used in experiment. Were the specimens without defects? If I look on figure 4, two lower pictures do not show perfect match as upper two (R²=0.54, R²=0.67). Write something in chapter “Materials and methods” about defects in plywood specimens. The part “Methods” is not well described. You utilized the sum of displacements (Table A1) in deriving the global modulus of elasticity (equation 1). It is desired, you should proved the validity of the sum (equation A1.1), because you introduced the two moduli of elasticity (global and bending). Please, write in manuscript which one of moduli is correct for plywood bending, may be, regardless on the configuration of loading. In figure 3, is deformation or displacement correct name of x-axis? Some of the conclusions are not supported with the results. Line 241, “The analyses suggest that a single strength value can be defined, independent of orientation and span-to-height ratio.“ – such experiment was not performed. Exclude this sentence, or add some research to promote the conclusion. Moreover, line 243, “wood-based structural components“, in general, were not reported in previous part of the manuscript. Change it into birch plywood.

Author Response

Dear authors,

response1: In Chapter 3, I added information on material defects. As a standard, we use the material as it comes from the market, including all defects. This is intended to ensure that variations in the characteristic values caused by such material defects are captured and incorporated into the dimensioning process.

If I look on figure 4, two lower pictures do not show perfect match as upper two (R²=0.54, R²=0.67).

response2: I have added some comments on the coefficients of determination

Write something in chapter “Materials and methods” about defects in plywood specimens. The part “Methods” is not well described. You utilized the sum of displacements (Table A1) in deriving the global modulus of elasticity (equation 1). It is desired, you should proved the validity of the sum (equation A1.1), because you introduced the two moduli of elasticity (global and bending). Please, write in manuscript which one of moduli is correct for plywood bending, may be, regardless on the configuration of loading.

response3: After Figure 3, I've added an explanation of the deformations and modulus values. I hope this makes it easier to understand.

In figure 3, is deformation or displacement correct name of x-axis?

response4: From my point of view, deformation is the correct name.

Some of the conclusions are not supported with the results. Line 241, “The analyses suggest that a single strength value can be defined, independent of orientation and span-to-height ratio.“ – such experiment was not performed. Exclude this sentence, or add some research to promote the conclusion.

response 5: You are absolutly right. I've removed this sentence.

Moreover, line 243, “wood-based structural components“, in general, were not reported in previous part of the manuscript. Change it into birch plywood.

response6: I changed it.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Dear authors,

In chapter of Methods, figure 3 is incomplete, because there was not shown axis “Force” and deformation should be replaced by displacement as below capture indicates.

Author Response

Dear authors,

In chapter of Methods, figure 3 is incomplete, because there was not shown axis “Force” and deformation should be replaced by displacement as below capture indicates.

Thanks for the comment. I've revised Figure 3.

Author Response File: Author Response.docx