2005 Fiscal Year Final Research Report Summary
Development of Ultrascnic Flaw Detection System for Quantitative Evaluation of Fatigue Damage of Existing Steel Structures
| Project/Area Number |
15206055
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
MIKI Chitoshi Tokyo Institute of Technology, Graduate School of Science and Engineering, Professor, 大学院・理工学研究科, 教授 (20016645)
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| Co-Investigator(Kenkyū-buntansha) |
HIROSE Soichi Tokyo Institute of Technology, Graduate School of Information Science and Engineering, Professor, 大学院・情報理工学研究科, 教授 (00156712)
SHIRAHATA Hiromi Musashi Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (40298013)
YAMADA Masaki Tohoku University, School of Engineering, Research Associate, 大学院・工学研究科, 助手 (30323083)
SASAKI Eiichi Yokohama National University, Graduate School of Environment and Information Sciences, Associate Professor, 大学院・環境情報研究院, 助教授 (40311659)
KIMOTO Kazushi Tokyo Institute of Technology, Graduate School of Information Science and Enginnering, Research Associate, 大学院・情報理工学研究科, 助手 (30323827)
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| Project Period (FY) |
2003 – 2005
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| Keywords | Steel Structures / Ultrasonic Testing / Fatigue Damage / Probes / Weld Defects |
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| Research Abstract |
This study considered following items and show the possibility of developing UT system for quantitative evaluation.
1. Development of a database for the fatigue crack detection in existing steel structures and consultation system based on the database :
The database of the location, cause, and retrofit work of the fatigue damage was developed and it was showed that the importance of the detection of cracks from defect for the maintenance.
2. Numerical simulation about characteristic of ultrasonic echo :
In order to develop linear array flaw detection system, wave propagation simulation was carried out to optimize the arrangement of piezoelectoric device in proves. Then effective arrangement for 2 MHz and 5 MHz were proposed.
3. Verification of the characteristics of ultrasonic echo from fatigue crack :
It was showed that crack tip opening and closing behavior could be detected as the change of ultrasonic echo intensity non-destructively, and that possibility of fatigue crack identification by visualization using SAFT technique.
4. Development of array ultrasonic flaw detection system :
Three dimensional flaw detection systems in steel using tandem or two dimensional array probes were developed.
5. Improvement of the accuracy of ultrasonic flaw detection systems by signal processing :
Three dimensional visualization techniques with high objectivity and accuracy was developed. Accuracy of visualization to detect the location of crack tip by SAFT technique etc was evaluated.
6. Verification by experiment using steel structural models :
Ability of the weld defects detection was verified by using the model of steel bridge frame piers, which is fatigue problem was found recently, then it was checked that internal weld defects can be detected accurately even if the defect had three dimensional shapes.
From the these results, it can be established that ultrasonic flaw detection system to evaluate fatigue damage objectively.
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