数値粒状体モデルの一般的増分挙動 General incremental behavior of idealized granular media
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To investigate how the incremental behavior of granular media deviates from the conventional plasticity theory, a series of numerical tests were carried out in terms of Granular Element Method. The model specimen used for the numerical tests was a random assembly of spherical particles with different radii; the particles were packed with an isotropic pressure in a spherical region. The numerical tests were the combination of several proportional loadings in the pi-plane to get sheared stress states and subsequent series of stress-probe tests to investigate plastic responses at these sheared stress states. The important features of plastic responses were found to be characterized in terms of a reference plane in stress space that includes the loading path and the line that connects the origin of stress space and the current stress point. As far as stress probes within this reference plane concerned, the plastic response seemed to be predicted almost by the non-associated flow rule. On the other hand, the incremental behavior for other stress-probe directions were totally different. The direction of incremental plastic strain was apparently dependent on the direction of incremental stress, and the existence of unique yield surface could never be assumed.
- NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan
NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan 54(0), 217-217, 2005
National Committee for IUTAM