The Mechanical Properties of Wood-Based Grid Sandwich Structures

Round 1

Reviewer 1 Report

Dear authors,

The manuscript was improved according to all reviewers suggestions. 

For this reason I reccomend its publication in present form.

Reviewer 2 Report

Good work.

The article has been modified according to the recommendations specified in my Report.

I consider that essential improvements have been made as a result the article can be published in this form.

Reviewer 3 Report

The manuscript was significantly improved during revisions.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Article forests-1678488

I am writing about the manuscript-ID forests-1678488, “Design and Compression Performance of Lightweight 2 Wood-Based Sandwich Structure”.

It is a study with a comprehensive introduction section. The methods are clearly described, with theoretical part and experimental part.

The results are well interpreted followed by discussion.

Conclusion section needs small improvement regarding more detailed findings of this study.

For all these reasons I suggest "small revision".

Reviewer 2 Report

forests-1678488

General comment

Authors should follow IMRAD scheme.

The authors describe the effect of the construction of sandwich based composite made of various materials. This is a relevant topic that falls within the scope of the journal. However, i can not recommend publication due to the following reasons:

• Manuscript is not following IMRAD structure
• The introduction is not providing background of the problem
• Objectives are not clear.
• Methods are not described
• There is no statistics

Introduction

L28, Please replace weight with mass

L28-29, sandwich structures can reduce the consumption of all materials. All materials are expensive. There is no need to emphasize the non-renewable materials in a manuscript working on renewable materials.

L31, please provide the reference for this statement. Please provide actual data. Besides that, aluminium and glass play an important role as well.

L33; please provide a reference for the respective statement. Which materials were considered? Wood? Steel? Please provide more details? Do you have recycling in mind?

L34-35; current strategies are not in line with the respective statement. Authors should consider both aspects. For example, EU Green deal is forecasting a reduction of non-renewable materials by 55% in 15 years! Please revise the respective manuscript with state of the art policies.

L35-36; less mature tree is associated with wood from plantations. Please provide a clear statement of which regions face this problem and put it to a global economic perspective. What are the glčobal volumes of juvenile wood and the ratio on the market in % compared to mature wood?

L50-102; This chapter is hard to read. Various composite systems are presented rather non-systematically. I can not see a red line. I suggest the authors to rewrite the paragraph.

• First present the first publications where respective structures are described in the world literature
• Please provide the current state of the art in the industry. Which technical solutions were scaled up, and which ones remained on low TRL.
• What are the current weaknesses in the sandwich based composites
• How are you addressing these weaknesses?

Why are you performing experiments with birch and larch? Is a comparison of massive wood and OSB/WPC comparable?

Why did you choose the respective materials? Why WPC?

Please refine the objectives? What is the main question? Are respective questions theoretical, or there is commercial potential. Are proposed solutions economically feasible? 

Material and methods

L132; is the respective OSB board from Germany or China?

L133, there should be space between the number and unit as per SI rules.

L136, missing space after the parenthesis

L137, certain parts of the methods are not in line with the objectives. Objectives stated that there is a larch wood, while plywood is listed in the methods. Please check the text carefully.

L139, how did you produce birch rods? These rods are not standard in all of the building practices? Please provide more details.

Fig 1, what was the length/width of the respective elements? How are these sandwich elements connected? Is the sketch correct, or the edges should be marked differently? Edges of elements in fig 1 and 3 are not the same?

How did you apply adhesive? What is the amount of adhesive per rod?

There are no statistics!

The number of replicates is not resolved?

All methods are not described, e.g. mechanical testing,

Experiments

Authors should not mix the results with methods. Table 2 should be moved to the results section.

Why there are not the same materials used for both composite structures.

How to compare so different materials?

Results and discussion

Certain pat of the results are included in the experimental? The manuscript should be reorganised.

Fig 9, are respective curves typical, average or the only curves?

Fig 10, there are deviation measures on the graph? What are they indicating?

Please perform statistical analysis between various constructions.

Figure 16, who is the author of this image?

It is impossible to assess the results and conclusions without a proper description of the methods and without statistics.

Reviewer 3 Report

It is a good and valuable work. There are some repeating passages and missing data. Please, check and modify according to the suggestions in the Report.

Comments for author File: Comments.pdf

Reviewer 4 Report

The review report, manuscript "Design and Compression Performance of Lightweight Wood-Based Sandwich Structure".

Suggestions:

Please be more specific in the manuscript Title about the content of your manuscript.

Please add some results of your research to the abstract. 

Line 29: Please add some references to this statement.:

Line 30: Comparing to which industries, please?

Line 31-33: Please add references to these statements.

Line 35: which material do you mean by non-renewable raw material, please? Be more specific.

Line 35: What do you mean by wood-based materials, please?  Wood composites? Engineered wood products?

Lines 50-90: Please check also 10.1016/j.matdes.2019.108159, 10.1007/s00107-014-0782-z, 10.3390/ma14175064, 10.13073/0015-7473-61.5.381

Lines 108-113: This part belongs to the Material and Methods section.

Line 118-127: This is not a goal, this is a research methodology, please formulate a goal of your research and move the methodology into Part 2.

Please add technical sheets or more information about the OSB, timber, plywood etc.

Lines 153-155: Please use italics for physical quantities.

Lines 358-359: Please check the equation (10) it is not explained what you used for F(A).  Also in equation (13), it is not correct to express E using E on the other side of the equation. Please check equations 7-13.

The rest of the Results section is well written, except for missing discussion with other authors.

Please add also limitations to the Conclusions part.