Improvement of nondestructive decay testing by sonic tomography

2017 Fiscal Year Final Research Report

• Project/Area Number: 26292079
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Forest science
• Research Institution: The University of Tokyo
• Principal Investigator: YAMADA Toshihiro 東京大学, 大学院農学生命科学研究科(農学部), 教授 (30332571)
• Co-Investigator(Kenkyū-buntansha): 太田 祐子 日本大学, 生物資源科学部, 教授 (60343802) ; 山下 香菜 国立研究開発法人森林研究・整備機構, 木材加工・特性研究領域, 主任研究員 (60353900) ; 伊藤 進一郎 三重大学, 生物資源学研究科, 招聘教授 (90092139)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 樹木 / 材腐朽 / 腐朽危険度診断 / 非破壊検査 / 音響波 / 共振周波数 / 材強度 / 人工腐朽

Outline of Final Research Achievements

The sonic tomography, two dimensional images of velocity distribution, was applied on wood disks with artificially chiseled cavities. As cavity area increased, the sound velocity shifted to a lower side and the estimated decay-area increased. Irregular shapes of cavities caused overestimation of cavity area.
Reduction of wood weight, sound velocity and wood strength was measured after inoculating wood decay fungi on test pieces of heartwood. During the progress of wood decay, reduction of sound velocity correlated linearly with weight loss. However, especially in early stage, wood strength was greatly reduced than weight and sound velocity.
Consideration of these results improve the accuracy of nondestructive decay testing using sonic tomography.

Free Research Field

樹木医学