| Project/Area Number |
15K14018
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Multi-year Fund |
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| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
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| Research Institution | Gunma University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
中畑 和之 愛媛大学, 理工学研究科(工学系), 教授 (20380256)
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| Co-Investigator(Renkei-kenkyūsha) |
MARUYAMA Shin-ichi (60344925)
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Project Status |
Completed (Fiscal Year 2017)
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| Budget Amount *help |
¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
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| Keywords | 非線形超音波 / 高調波 / 分調波 / 境界要素法 / 粒子法 / 非破壊評価 / 超音波非破壊評価 / き裂 / 非線形超音波法 / 時間領域境界要素法 / 共振現象 / 演算子積分時間領域境界要素法 |
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| Outline of Final Research Achievements |
In recent years, a new ultrasonic nondestructive evaluation method that utilizes nonlinear ultrasonic behavior generated in cracks or at a bi-material interface defect has emerged. However, the mechanism of generating subharmonics is theoretically still not well understood. Therefore, in this research, dynamic contact problems of a bi-material interface defect and a crack with contact boundary conditions are investigated by using numerical methods such as the convolution quadrature time-domain boundary element method (CQBEM), moving particle semi-implicit simulation, and elastodynamic finite integration technique. In addition, some crack shape reconstruction methods are developed based on the inverse scattering theory, and the applicability is considered. Numerical results show that the subharmonic generation is depend on the angle of incident ultrasonic waves, quasi-natural resonance frequency, and contact boundary conditions.
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