Stiffness and Strength Evaluation of Wood Considering The Effect of Internal Cracks due to Kiln Drying

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02299
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 23010:Building structures and materials-related
• Research Institution: Kyushu University
• Principal Investigator: Sato Toshiaki 九州大学, 人間環境学研究院, 准教授 (00637887)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 人工乾燥 / 内部割れ / 欠点 / 強度 / 剛性 / 靭性

Outline of Final Research Achievements

Drying is indispensable for wood used in buildings, and kiln drying, which completes the process in a short period of time, is the popular method of drying today. It is not clear how cracks affect the stiffness and strength expected of structural members.In this study, CT scans were used to supplement information on the interior of wood. Furthermore, by using image analysis in full-scale bending tests, we investigated the effect of wood defects including internal cracks on fracture phenomena. In addition, we investigated the movement of water in wood, which is a factor in cracking.

Free Research Field

建築構造

Academic Significance and Societal Importance of the Research Achievements

木材は様々な力学的性質を持つ. 天然材料であるが故に成長環境に左右され, 完全に同一の個体がないことから, 予め強度・剛性を知ることが難しい. また同じ個体内でも位置により強度・剛性が異なる不均質性も併せ持つ. さらに, 木材内部の水分量, 厳密には結合水が力学的性質に影響を及ぼすことで知られ, これらの性質を勘案して安全に利用するために, これまでは統計的な手法を基にその強度体系を支えてきた. 一方, 近年多様化したその利用用途を勘案すれば, より詳細な検討が不可欠で, 本研究の学術的価値は, 可能な限り条件を絞りこみ, その強度・剛性の評価を試みた点にある.