| Project/Area Number |
21360215
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Kyushu University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
SAGAWA Yasutaka 九州大学, 大学院・工学研究院, 准教授 (10325508)
BEPPU Yasutiaka 防衛大学校, 建設環境工学科, 准教授 (90532797)
ASAI Mitsuteru 九州大学, 大学院・工学研究院, 准教授 (90411230)
TAMAI Hiroki 九州大学, 大学院・工学研究院, 助教 (20509632)
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| Project Period (FY) |
2009 – 2011
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| Project Status |
Completed (Fiscal Year 2011)
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| Budget Amount *help |
¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000)
Fiscal Year 2011: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
Fiscal Year 2010: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
Fiscal Year 2009: ¥12,090,000 (Direct Cost: ¥9,300,000、Indirect Cost: ¥2,790,000)
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| Keywords | 回転式打音検査 / コンクリート構造物 / 非破壊診断 / 音響解析 / 回転式打音法 / 浮き・剥離 / 音圧スペクトル / 自己組織化マップ / SOM / 構造振動 |
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| Research Abstract |
Recently, it becomes very important to maintain the existing(aging) reinforced concrete structures in Japan. In order to minimize their life-cycle cost, many researches on the nondestructive evaluation technique have been conducted. However, most of nondestructive tests have problems related to their expense or measurement condition. Thus, visual inspection and conventional hammering sound test are usually applied as an effective method. But, the hammering sound test requires a high degree of skill to evaluate hammering sound and theoretical investigation has not well conducted on the acoustic mechanism of the hammering sound test. Therefore, this study appraises the capabilities of conventional hammering test and the rotary hammering test by means of the experiment using mortar specimens and existing bridges. Furthermore, acoustic analysis based on finite element method is conducted in order to grasp influences of defect on the hammering sound. The following results are obtained in this study.
1)It is recognized that maximum sound pressure increase due to the existence of inner defect.Whereas,damping performance decrease due to the effect of defect.
2)We confirmed the results of rotary hammering sound test shows clear adn significant influence of inner defect on their impact sounds. Therefore as for the diagnostic capability, the rotary hammering test is superior to conventional hammering test.
3)Identification of defect condition by sound pressure information was attempted using the Self-Organizing Map algorithm and it is confirmed that the size of defect was clearly identified using the result of SOM.
4)In addition,combination use of sound pressure and frequency information by time-frepuency analysis could evaluate precise defect conditions.
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