1994 Fiscal Year Final Research Report Summary
Analysis of Ultimate Strength Properties of Construction Materials by a Microscopic Approach
| Project/Area Number |
05650426
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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 |
土木材料・力学一般
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
IWAKUMA Tetsuo Tohoku University, Dept.Civil Eng., Professor, 工学部, 教授 (60120812)
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| Co-Investigator(Kenkyū-buntansha) |
KISHINO Yuji Tohoku University, Dept.Civil Eng., Associate Professor, 工学部, 助教授 (00005448)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Micromechanics / Granule / Layred media / Non-local / Instability / Kink band / Localization |
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| Research Abstract |
This research puts emphasis on layred materials which can be the simplest model of construction composite materials in future. One example is for estimation of compressive strength of fiberous materials and an approach of structural mechanics is used to analyze their microscopic behavior. These materials are to be considered as structural materials which are light but have high strength. A simple model of Timoshenko beam theory reveals that the compressive strength is highly affected by anisotropy due to resisting properties between layrs in shear. Also kink bands which often observed in actual testing of such composite materials are also predicted. Not only qualitative property of the compressive strength but also directions of such kink bands are evaluated numerically for multi-layrd beam columnms and are compared with experimental results and observatons of real carbon fibers.
Another example is for soils. Especially a property due to granular components of such materials is modelled by the non-local theory. Namely a constitutive law using such a non-local approach is used to predict material instability in shear. Several numerical examination reveal that the instability is more likely activated by the non-locality. Moreover the non-locality results in a simple prediction that there exist a certain limit on numbers of granules which is inside the localized band.
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