1990 Fiscal Year Final Research Report Summary
A Study on the Application of Inelastic Constitutive Relations under Plasticity-Creep Interaction and the Evaluation of Life Prediction Methods
| Project/Area Number |
01302026
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
材料力学
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| Research Institution | Kyoto University |
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Principal Investigator |
INOUE Tatsuo Kyoto University, Department of Mechanical Engineering, professor, 工学部, 教授 (10025950)
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| Co-Investigator(Kenkyū-buntansha) |
IGARI Toshihide Mitsubishi Heavy Industries, Ltd., Nagasaki Research Institute, Researcher, 長崎研究所, 研究員
KAWAI Masamichi University of Tsukuba, Division of Structure Engineering, Lecturer, 構造工学系, 講師 (90169673)
YOSHIDA Fusahito Hiroshima University, Division 1, Assoc, Prof., 工芸部, 助教授 (50016797)
OHNO Nobutada Nagoya University, Department of Mechanical Engineering, Assoc, Prof., 工芸部, 助教授 (30115539)
IMATANI Shoji Kyoto Institute of Technology, Department of Mechanical Systems, Assoc. Prof., 工芸学部, 助教授 (70191898)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Plasticity-creep Interaction / Fatigue-creep Interaction / Inelastic Constitutive Relation / Life Prediction / Finite Element Analysis / Unified Constitutive Relation |
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| Research Abstract |
The first Part of this report covers the extension of the second phase project, and presents more developed results on the applicability of the constitutive models and life prediction methods, respectively, to the multiaxial stress state of combined tension-compression and cyclic torsion. The results of analysis were compared with the experimental data.
The motivation of the second part concern the third phase of the project which arises from engineering requirement that the schemes are to be used for practical design purposes : Applicability of the inelastic constitutive models to finite element calculation is examined by comparing the analytical stress/strain response near notch root of the bar with experimental results, and fatigue-creep lives of the specimen are evaluated by applying the life prediction methods.
Four loading patterns such as creep loading, fast-fast and slow-slow cyclic straining and fast-fast cyclic straining with a tension hold-time were applied to the specimen. The results of analysis of stress/strain simulation were compared with measured strain at notch root by means of "Strain-Pecker", a capacitance type extensometer for high temperature use. The predicted crack initiation Life was also confirmed by the experimental lives which were detected by a direct current potential drop technique, and failure life was defined as the cycles of 25% stress drop from saturation.
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