Measurement and Improvement of Wood Mechanical and Chemical Properties

A special issue of Forests (ISSN 1999-4907). This special issue belongs to the section "Wood Science and Forest Products".

Deadline for manuscript submissions: 23 September 2024 | Viewed by 2907

Special Issue Editors


E-Mail Website
Guest Editor
College of Materials Science and Engineering, Nanjing Forestry University, Longpan Road 159, Nanjing 210037, China
Interests: wood mechanical behavior; wood materials microstructure

E-Mail Website
Guest Editor
College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China
Interests: nanotechnology; wood chemistry; biotechnology; materials engineering
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Guest Editor
Research Institute of Forestry New Technology, Chinese Academy of Forestry, Beijing 100091, China
Interests: wood-based materials; wood anatomy; carbonization; wood charcoal analysis

Special Issue Information

Dear Colleagues,

Wood is a renewable resource that has been widely used in construction field. Mechanical and chemical properties are crucial for evaluating wood based products. It is important to use standard and state-of-the-art techniques to evaluate the mechanical and chemical properties of wood. Good evaluation certainly contributes to effectively improve mechanical and chemical properties of wood. The aim and scope of the Special Issue publishes original scientific research results and review papers covering the entire field of wood material science, wood components and wood based products. Subjects are wood quality, wood physics and physical technologies, wood chemistry and chemical technologies. Latest advances in areas such as cell wall and wood formation; structural and chemical composition of wood and wood composites and their property relations; physical, mechanical and chemical characterization and relevant methodological developments are reported. Topics related to wood technology include wood mechanics, creep and rheology are included. Papers are helpful for understanding and improving the mechanical and chemical properties of wood are welcomed.

Dr. Wanzhao Li
Dr. Xinzhou Wang
Dr. Yue Qi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Forests is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • wood
  • mechanical properties
  • chemical properties
  • structure
  • new technologies
  • improvement

Published Papers (3 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

10 pages, 3920 KiB  
Article
Comparative Studies on Tensile Mechanical Properties of Water-Saturated Earlywood and Latewood within the Same Growth Ring from Masson Pine
by He Huang, Zhu Li, Yuan Li, Jiali Jiang and Ruiqing Gao
Forests 2024, 15(4), 589; https://doi.org/10.3390/f15040589 - 25 Mar 2024
Viewed by 671
Abstract
The tensile mechanical behavior of water-saturated earlywood (EW) and latewood (LW) within the same growth ring of Masson pine (Pinus massoniana) was investigated in the hydrothermal environment and discussed with respect to the density and microfibril angle (MFA) of the wood [...] Read more.
The tensile mechanical behavior of water-saturated earlywood (EW) and latewood (LW) within the same growth ring of Masson pine (Pinus massoniana) was investigated in the hydrothermal environment and discussed with respect to the density and microfibril angle (MFA) of the wood specimens. The tensile modulus, tensile strength, and strain at failure of EW and LW in the longitudinal (L) and tangential (T) directions were determined at different temperature levels ranging from 30 °C to 80 °C. Major differences in the tensile mechanical properties were found between EW and LW in the L and T directions. Compared to LW, EW showed a smaller density and a larger MFA, resulting in a lower tensile modulus, lower tensile strength, and higher strain at failure. Compared to the L specimens, the T specimens showed lower tensile modulus, lower tensile strength, and higher strain at failure. As the hygrothermal temperature increased, the MFAs, tensile modulus, and tensile strength of EW and LW specimens decreased, except for the MFAs of LW, while the strain at failure of the specimens showed the opposite trend. Variations in the tensile mechanical behavior between EW and LW were mainly influenced by the density and MFA of the specimens, and are closely associated with the hydrothermal softening properties of wood. These findings contribute to a further understanding of the structural–mechanical relationships of Masson pine wood at the cell wall level, and provide a scientific basis for the better utilization of plantation softwood in the hydrothermal environment. Full article
Show Figures

Figure 1

11 pages, 8166 KiB  
Article
Understanding the Effect of Knots on Mechanical Properties of Chinese Fir under Bending Test by Using X-ray Computed Tomography and Digital Image Correlation
by Xie Zhang, Huibo Sun, Gangbiao Xu, Yanjun Duan, Van den Bulcke Jan, Van Acker Joris and Jiangtao Shi
Forests 2024, 15(1), 174; https://doi.org/10.3390/f15010174 - 15 Jan 2024
Viewed by 905
Abstract
Knots in wood have a substantial impact on both the physical and mechanical properties of derived products. It is necessary to study their effect on the mechanical properties of wood and understand the mechanisms behind the effect. The modulus of elasticity (MOE) and [...] Read more.
Knots in wood have a substantial impact on both the physical and mechanical properties of derived products. It is necessary to study their effect on the mechanical properties of wood and understand the mechanisms behind the effect. The modulus of elasticity (MOE) and modulus of rupture (MOR) of specimens without knots and with knots are measured using the three-point bending test. The size and position of knots are recorded. The specimens with knots are analyzed according to failure not at knots and failure at knots. For specimens with failure at knots, they are further divided into two sub-groups, i.e., failure around knots (FK-A) or failure in knots (FK-I). Full article
Show Figures

Figure 1

13 pages, 4384 KiB  
Article
The Impact of Earlywood and Latewood on the Compressive Stress of Thermally Modified Douglas Fir
by Junfeng Wang, Kai Yang, Wanzhao Li, Xinzhou Wang, Jan Van den Bulcke and Joris Van Acker
Forests 2023, 14(7), 1376; https://doi.org/10.3390/f14071376 - 5 Jul 2023
Viewed by 867
Abstract
Thermal modification can increase the physical stability and impact the mechanical strength of wood. It is necessary to understand the effects of modifications on the compressive stress of wood. In this study, Douglas fir (Pseudotsuga menziessi) blocks were modified at 180 [...] Read more.
Thermal modification can increase the physical stability and impact the mechanical strength of wood. It is necessary to understand the effects of modifications on the compressive stress of wood. In this study, Douglas fir (Pseudotsuga menziessi) blocks were modified at 180 °C (TM-180 °C) and 210 °C (TM-210 °C). The compressive stress of pure earlywood (EW), pure latewood (LW), and combined earlywood and latewood (ELW) specimens was measured. The specimens were compressed at 30% of their original thickness, and during the compression test the strain distribution of the ELW was recorded. In addition, the microstructures before and after compression were investigated, complemented with SEM to understand the structural changes taking place. The results showed that the compressive stress of the TM-180 °C specimens was the highest because the thermal modification increased the stiffness of cell walls and the homogenized strain distribution in the ELW specimens. The control specimens had a higher compression set recovery rate than the thermally modified specimens. The tracheid cell walls in the EW and LW specimens were flattened and buckled, respectively, due to compression. In the thermally modified materials, cell wall fissures and wood ray fractures in the EW and LW specimens, respectively, were observed. For the ELW specimens, the structural changes in the latewood were not obvious and the structural changes in the earlywood were less significant than in the full EW specimens. Compared to the EW specimens, the earlywood in the ELW specimens showed higher compression set recovery rates. It seems that structural failure in earlywood is limited when used in combination with latewood, resulting from the homogenized strain distribution in earlywood. Full article
Show Figures

Figure 1

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Understanding the effect of knots on mechanical properties of Chinese fir under bending test by using X-ray CT and DIC
Authors: Xie Zhang; Huibo Sun; Jiangtao Shi; Fan Huang; Yanjun Duan; Jan Van den Bulcke; Joris Van Acker
Affiliation: Nanjing Forestry University
Abstract: Knots in wood have a substantial impact on both the physical and mechanical properties of derived products. It is necessary to study their effect on mechanical properties of wood and understand the mechanisms behind the effect. MOE and MOR of specimens without knots and with knots are measured using three point bending test. Size and position of knots are recorded. The specimens with knots are analyzed according to failure not at knots and failure at knots. For specimens failure at knot, they are further divided into failure in knots (FK-I) and failure around knots (FK-A). Shear strain was recorded during the bending test using digital image correlation. After the bending test, the internal structure of the specimens was visualized using X-ray CT. The MOE and MOR differences among specimens without knots, knot specimens failure not at knots and FK-A is limited. MOE of FK-I is lower than that of FK-A specimens. MOR of FK-I is significantly lower than that of FK-A specimens at the 1% level. The specimens failure in knots is because of small size of knots and large distance between knot and loading wedge, resulting in failure at knots (including around and in knots) and failure in knots respectively. Knots can hinder strain transferal and cause strain accumulation as well as a few large cracks, resulting in low MOE and MOR. If knots have limited impact on strain transferal, structural changes would include a large number of both large and small cracks, resulting in a high MOE and MOR.

Back to TopTop