| Project/Area Number |
06650529
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
構造工学・地震工学
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| Research Institution | Daido Institute of Technology |
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Principal Investigator |
KOTOGUCHI Hisao Daido Institute of Technology, Civil Engineering, Professor, 工学部, 教授 (60047305)
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| Co-Investigator(Kenkyū-buntansha) |
MIKI Toshihiro Daido Institute of Technology, Civil Engineering, Associate Professor, 工学部, 助教授 (90137175)
MIZUSAWA Tomisaku Daido Institute of Technology, Civil Engineering, Professor, 工学部, 教授 (60113081)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1994: ¥800,000 (Direct Cost: ¥800,000)
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| Keywords | Fatigue / Corrosive Fatigue / Microcrack / Occurrence of Crack / Fracture Mechanics / Stress Intensity Factor / Process Zone / Crack Propagation |
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| Research Abstract |
1. Multiple initial cracks initiate and one of these cracks that has most developed process zone has microcrack. Microcrack propagated along the grain boundary.
2. In the behavior of microcrack propagation, there were three steps. In the first step, process zones 1 the crack propagated along the grain boundary in zigzag direction, near the root of two process zones. microcrack stopped propagating until growing of new process zone. Microcrack propagated by the this behavior.
It has been able to estimate relationship between microcrack growth rate and stress intensity factor has found to propagate when K is less than its lower limit of long crack that is general consideratic crack growth rate in microcrack decreased in accordance with an increase of stress intensity factor.
4. Behavior of crack opening and closure was found to occur even in microcrack.
Fractogragrapy of corrosive and atmospheric fatigue crack are permed by scanning electron microsc clear the difference in two types environments.
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