Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Although embedment properties are vital to timber engineering, the behavior and strain distributions in wood-based panels have not been clarified in detail. Our early studies suggested four possible causes of failure behavior and strain distribution: (i) two types of failure behavior (in-plane and out-of-plane failure); (ii) enlargement of the stress-spreading range with increasing load step; (iii) reduction of the stress-spreading range (normalized by dowel diameter) with increasing dowel diameter; and (iv) preferential stress spreading in the vertical and horizontal directions along the strong and weak-axis specifications, respectively. However, these hypotheses were not supported by actual observations. The present study aims to observe and clarify the surface strain distribution via digital image correlation and the internal failure behavior via computed tomography scanning. Most results of the wood-based panel specimens (plywood and oriented strand board) did not contradict the above hypotheses. The failure behaviors of plywood and oriented strand board are likely determined by the direction of the veneer fibers and the layer’s position, respectively. Within the strong axial layer of plywood, fibers on both sides of the dowel were densified by fibers dissociated immediately above the dowel, whereas the weak axial layer in plywood was deformed like a timber under partial compression perpendicular to the grain. In contrast, oriented strand board under an embedding stress exhibited a circularly distributed strain and a dispersed void area in its outer layer. Densification was observed only in the inner layer.

DOI： 10.1186/s10086-023-02113-1

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Other Link： https://link.springer.com/article/10.1186/s10086-023-02113-1/fulltext.html

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

Abstract

Embedment properties are vital to timber structural designs, and many types of wood-based structural panels have been developed for diverse uses. Comprehensive and systematic studies regarding the embedment properties of wood-based structural panels are limited. In this study, a jig that allows the observation of fracture processes is developed, and a monotonic tensile embedment test is conducted on plywood, oriented strandboard (both strong and weak axes), particleboard, medium density fiberboard, and hardboard. The parameters used in the test are the dowel diameter, pilot hole size, and end and edge distances. The effects of these parameters on the embedment properties (i.e., the failure mode, ductility, maximum stress, and yield stress) are discussed comprehensively. The failure mode is determined by the edge distance. At a sufficient edge distance, ductile failure occurs, and the load is maintained until the remaining end distance reaches a certain value. The maximum stress and yield stress are analyzed quantitatively via standardized multiple regression analysis. The results suggest the following: (i) The ratio of the in-plane strength to the internal bond strength is related to the failure behavior; (ii) the dowel diameter, fiber direction, and load levels affect the stress spread pattern of the embedment pressure.

DOI： 10.1186/s10086-023-02093-2

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Other Link： https://link.springer.com/article/10.1186/s10086-023-02093-2/fulltext.html

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Architectural Institute of Japan  

DOI： 10.3130/aijs.86.945

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Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Society of Materials Science, Japan  

DOI： 10.2472/jsms.70.264

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