| Project/Area Number |
60550045
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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 |
機械材料工学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SHOJI TETSUO FACULTY OF ENGINEERING, TOHOKU UNIV., ASSOCIATE PRFESSOR, 工学部, 助教授 (80091700)
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| Co-Investigator(Kenkyū-buntansha) |
TAMAKAWA KINJI FACULTY OF ENGINEERING, TOHOKU UNIV., RESEARCH ASSOCIATE, 工学部, 助手 (30005368)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1986: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1985: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Keywords | Finite Element Method / Time domain Analysis / Crack Tip Strain Rate / LWR Pressure Vessel / Pressurized High Temperature Water / Slow Strain Rate Test / 臨界電位 / 破壊力学 |
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| Research Abstract |
BY APPLYING FRACTURE MECHANICS APPROACH TO SSRT AS A ASSESSMENT TECHNIQUE OF STRESS CORROSION CRACKING SUSCEPTIBILITY, IT BECAME POSSIBLE TO USE SSRT AS A QUANTITATIVE EVALUATION TECHNIQUE FOR STRUCTURAL INTEGRITY ASSESSMENT RATHER THAN QUALITATIVE ONE SUCH AS GO-NO GO SCREENING TESTS. MAIN CONCLUSIONS CAN BE SUMMARIZED AS FOLLOWS,
1. TIME BASE CRACK GROWTH RATE WAS FOUND AS A SUITABLE PARAMETER REPRESENTING CRACK TIP STRAIN RATE BY FEM ANALYSIS AND THIS FINDING GAVE A PHYSICAL BASIS TO THE TIME DOMAIN ANALYSIS.
2. SSRT TESTS WERE PERFORMED ON NUCLEAR REACTOR PRESSURE VESSEL STEELS, SA508 CLASS III AND SA533B CLASS I IN HIGH TEMPERATURE WATER BY USE OF PLAIN AND PRE-CRACKED SPECIMENS. CRACK INITIATION AND PROPAGATION BEHAVIOR WERE EVALUATED IN TERMS OF FRACTURE MECHANICS PARAMETERS AND, SPECIALLY, THRESHOLD BEHAVIOR AND CRACK GROWTH RATE WERE QUANTITATIVELY EVALUATED. THIS CRACK GROWTH RATE OBTAINED FROM SSRT WAS CAMPARED WITH THOSE OBTAINED BY CONSTANT LOAD SCC TESTS.
3. EFFECTS OF SULPHATE CONTAMINATION AND SULPHUR CONTENT IN STEEL ON CRACK GROWTH RATE, THRESHOLD BEHAVIOR AND SCC CRITICAL POTENTIAL WERE EXAMINED AND THE SIGNIFICANCE OF THESE EFFECTS IN STRACTURAL INTEGRITY ASSESSMENT WAS EMPHASIZED.
4. A NEW FLAW EVALUATION PROCEDURE TAKING INTO CONSIDERATION SUBCRITICAL CRACK GROWTH BASED UPON TIME DOMAIN ANALYSIS WAS PROPOSED AND NOW BEING REVIEWED BY INTERNATIONAL CYCLIC CRACK GROWTH RATE GROUP.
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