WOOD RESEARCH Volume 69, Number 3, 2024
ZANBIN ZHU, CHUNMEI YANG, WENJI YU, BO XUE, JIE YAN, YUCHENG LI, and TONGBIN LIU

FRACTURE MECHANISM ANALYSIS OF HIGH-DENSITY FIBREBOARD BASED ON DIGITAL IMAGE CORRELATION TECHNOLOGY

This paper analyses the scattering images of the bending deformation of high-density fibreboards based on the digital image correlation (DIC) technique, so as to study its mechanical deformation law. Three-point bending tests were carried out on fibreboards using a mechanical testing machine with a non-contact measuring system. The measured values of the displacements of the grid nodes in the region of interest (ROI) were combined with the Moving least squares (MLS) method to construct the strains of the high-density fibreboards at different loading forces, thus deriving the strain values of the fibreboards during the bending deformation process. To further analyze its force deformation mechanism, this paper used a portable electron microscope and scanning electron microscope to analyze the damage situation at the fracture damage, and at the same time, it verified that the constructed strain field model was accurate

WOOD RESEARCH Volume 65, Number 6, 2020
Quan Li, Renyuan Liu, Xiaoqian Chen, and Hui Lin

Box-Behnken design for process parameters optimalization of bamboo-based composite panel manufacturing

High performance bamboo-based composite panel taking bamboo mats, bamboo curtains and poplar veneers are used as raw material, is manufactured from the each layers slab was crisscrossed, impregnated with phenolic resin, compressed and cured. The product was optimized by Box-Behnken model design and data analysis. The results show that the best parameter conditions were hot pressing temperature of 140°C, hot pressing time of 94 s.mm-1, and hot pressing pressure of 2.5 MPa. The model was validated according to the optimal process parameters and the static bending strength (MOR), elastic modulus (MOE), thickness expansion rate of water absorbing, adhesive strength and density are 98.95 MPa, 8.81 GPa, 4.7%, 1.25 MPa, 0.89 g.cm-3, respectively. The actual value is close to the predicted value, confirming that the obtained model can accurately predict the MOR of the product using the three factors of hot pressing as variables under different conditions.

WOOD RESEARCH Volume 65, Number 4, 2020
Laércio Serenini Jr., Rafael Rodolfo De Melo, Diego Martins Stangerlin, and Alexandre Santos Pimenta

Wood quality of six eucalyptus clones planted in northern Mato Grosso State, Brazil

The present work had the goal of assessing the wood quality through physical-mechanical properties of six 5-year old eucalyptus clones currently planted in northern Mato Grosso State, Brazil. The following clones were assessed, five of them Eucalyptus grandis x Eucalyptus urophylla hybrids and one a clone of Eucalyptus camaldulensis. The physical-mechanical properties were basic density as a function of tree height; pith-to-bark direction; linear, tangential and radial shrinkage; and anisotropic coefficient, longitudinal and parallel compression and static bending strengths; and hardness. Eucalyptus grandis x Eucalyptus urophylla hybrids showed the best wood quality. Concerning to mechanical results, the clones reached intermediate values of strength and rigidity, qualifying them for use in structural applications with less stringent requirements. Considering that all the clones had juvenile wood, the mechanical properties were satisfactory, making the clones suitable for industrial uses.