1993 Fiscal Year Final Research Report Summary
Development of small specimen test techniques
| Project/Area Number |
04555185
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機工業化学・無機材料工学
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| Research Institution | Tokyo Institute of Technology |
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Principal Investigator |
ISEKI Takayoshi Tokyo I.T./Facul.of Eng., Prof., 工学部, 教授 (10016818)
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| Co-Investigator(Kenkyū-buntansha) |
YANO Toyohiko Tokyo I.T./R.L.N.R., Assoc.Prof., 原子炉工学研究所, 助教授 (80158039)
MIYAZAKI Hiroyuki Tokyo I.T./Facul.of Eng., Res.Assoc., 工学部, 助手 (30239389)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Small specimen / Bending Strength / Ceramics / Specimen size effect / Weibull distribution |
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| Research Abstract |
According to JIS R1601, bending strength of ceramics is evaluated with more than 10 specimens whose sizes are 3x4x36 mm. However, many standard specimens of this size are not available from neutron-irradiated materials because of limitations of irradiation space and irradiation waste. Therefore small specimen test techniques are necessary to measure mechanical properties of neutron-irradiated materials.
An adequate experimental method must be developed to get reliable data from small specimens because the strength of ceramics depends on testing condition. It is well known that the strength of ceramics depends on the specimen size. Estimation methods of the strength of larger volume component from that of smaller specimen are important as well. Therefore the size effect on the strength must be studied.
In this study, bend fixtures for small specimens were designed from the stand point of easy operation and precise measurement. A testing machine was also developed for small specimens because small specimens are fractured at much lower load and lower deflection than those of standard specimens. The effects of surface roughness, twisting and strain rate on the bending strength were studied. The testing condition was determined to minimize the errors. The size effect on the strength was studied with the bending fixtures and the testing condition. It was found that the size effect was well described by Weibull's scaling relationship of specimen size. Therefore estimation of the strength of the standard specimens from that of the small specimens seemed to be valid with the Weibull's relationship. Strength of irradiated AlN was actually measured with this technique.
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