A Study on Quantitative Estimation Method for Fatigue Crack Propagation Behavior by Image Analysis
| Project/Area Number |
12650471
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
構造工学・地震工学
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| Research Institution | Nagoya University |
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Principal Investigator |
TATEISHI Kazuo Nagoya University, Division of Environmental Engineering and Architecture, Associate Professor., 大学院・環境学研究科, 助教授 (80227107)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2001: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2000: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | fatigue / fatigue crack / image analysis / crack propagation rate / stress intensity factor / microscope |
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| Research Abstract |
In this study, a simple method to estimate fatigue crack propagation behavior by image analysis was proposed, and its applicability and limitations were experimentally investigated. Main results of this study is as follows, 1. On cruciform welded joints and web gusset, welded joints, experiments to measure the opening width offatigue crack by using a digital microscope, and estimate Mode I stress intensity factor for the crack were carried out. The test results showed that the stress intensity factor more than 10 Mpa/"m could be estimated with enough accuracy for engineering use.
2. In order to extend the applicability of the proposed method to real bridge structural members, crack opening behavior under cyclic loaded condition was recorded by a digital microscope and a digital video camera, and the proposed estimation was carried out. On the recorded digital movie data. When the frequency is less than 5Hz, crack opening width could be measured accurately.
3. The proposed method was applied to a real fatigue crack in steel bridge members. The crack showed opening/closing behavior clue to the passage of the vehicle, but. Their frequency was about Ihz, which is within the applicable condition of the proposed method.
4.The method to obtain the histograms of stress intensity factor and excessive probability was proposed from the continuously measured crack opening behavior.
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Report
(3 results)
Research Products
(19 results)
