Development of monitoring system for large structures by non-contact defect imaging technique

2016 Fiscal Year Final Research Report

• Project/Area Number: 26282094
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Social systems engineering/Safety system
• Research Institution: Kyoto University
• Principal Investigator: Hayashi Takahiro 京都大学, 工学(系)研究科(研究院), 准教授 (30324479)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 非破壊検査 / 非接触 / レーザ超音波 / ガイド波

Outline of Final Research Achievements

This study investigated defect imaging in plate-like structures using scanning laser source (SLS) technique, in which laser pulse for generating elastic wave is rastered over a plate and the elastic wave is detected at a fixed point on it. In this study, irradiating laser pulses at high repetition rate by fiber laser and modulating them enabled to generate narrowband burst elastic waves and improved signal level in frequency range. Moreover, it was theoretically and experimentally confirmed that averaging images at multiple frequencies provides clearer defect images. Using the experimental system with these functions, images of an inner wall-thinning were obtained for such a complex plate-like structures as a branched pipe by the measurements from 6 meters away.

Free Research Field

材料力学