1987 Fiscal Year Final Research Report Summary
Stereological Analysis of Diformation Mechanism of Granular Materials
| Project/Area Number |
60460156
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
基礎・土質工学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
SATAKE Masao Professor, Faculty of Engineering, Tohoku Univ., 工学部, 教授 (50005188)
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| Co-Investigator(Kenkyū-buntansha) |
NIISEKI Shigeru Research Associate, Faculty of Enqineering, Tohoku Univ., 工学部, 助手 (30005524)
KISHINO Yuji Associate Professor, Faculty of Engineering, Tohoku Univ., 工学部, 助教授 (00005448)
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| Project Period (FY) |
1985 – 1987
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| Keywords | Granular Materials / Simulation / Stereology / Dissipation Mechanism / Fabric Tensor / Fractal / Flow Rule |
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| Research Abstract |
The objective of this research is to investigate the complicated deformation mechanism of granular materials through the studies both on the microscopical behaviors of granular assemblies and on the statistical characteristics as continuum bodies.
In this research, a new simulation method for the granular assemblies in two dimensions was developed. The applications to various statical problems show that the mehod presented here is a useful tool for the investigations of mechanical behaviors of granular materials. Especially, it enables us to study in the way of the statistical approach which is represented by the stereological method. The main results obtained through the analyses using this method are the followings: (1) The distribution of dissipation energy calculated at each contact point has the fractal property that the mean value of the energy level is not specified (2) The total dissipation energy changes linearyl with the shear strain except for the sudden changes observed at the steps where the compactions are obsrved with the internal fabric changes. (3) The induced anisotrpy is characterized by a newly defined fabric tensor whose trace represents the co-ordination number and the minor principal value of the tensor changes remarkably with the development of anisotropy.
Through the consideration on the macroscopical behaviors of granular materials, several new ideas were presented. A new extremum proinciple for the work done by the deviational stress was proposed. Using this principle topether with approapriate dissipation functions, flow rules for the granular materials can be derived. A reasonable flow rule was derived through the statistical consideration on the dissipation mechanism in grnnular materials. Another new idea is the concept of the work increment tensor. Using this tensor, the Rowe's stress dilatancy equation in two dimensions was extended to the therr dimensional representation which has the suitable form as a tensor equation.
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