Quantitative nondestructive evaluation of water content distribution in materials or structures

2020 Fiscal Year Final Research Report

• Project/Area Number: 16H04395
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural engineering/Earthquake engineering/Maintenance management engineering
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: HIROSE SOHICHI 東京工業大学, 環境・社会理工学院, 教授 (00156712)
• Co-Investigator(Kenkyū-buntansha): 古川 陽 東京工業大学, 環境・社会理工学院, 助教 (60724614)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: ガイド波 / 分散特性 / 鋼板接着損傷評価 / 電磁波レーダ / カルマンフィルタ / スパース解

Outline of Final Research Achievements

The purpose of this study is to estimate the water content distribution inside materials or structures by nondestructive measurement using ultrasonic and electromagnetic waves. In the ultrasonic nondestructive measurement, it was shown that the presence of stagnant water in layered structures and the thickness of the water layer can be estimated by using the dispersion characteristics of ultrasonic guided waves in layered structures. In the field of electromagnetic wave measurement, we developed an algorithm for estimating the water content in soil using the Kalman filter theory based on the reflection coefficient of electromagnetic waves.

Free Research Field

応用力学

Academic Significance and Societal Importance of the Research Achievements

材料・構造物内部の水分の存在は，構造物の強度や寿命に大きな影響を及ぼすことから，構造物の維持管理を行う上で水分量の分布や時間変化を把握することが重要である．従来の水分量計測はあらかじめ内部に計測装置を埋め込むことによって「点」情報を得る手法が主流であった．本研究では超音波探触子や電磁波レーダなどの非破壊計測装置を用いて一度に広範囲な水分量分布を効率的に求めることを可能にしており，得られた研究成果の意義は大きい．