Megumi YABUUCHI

Research on Influence of Plastic Flow Rule on Soil Material and Bifurcation Analysis Method

principal adviser Kunio Torii


A destroying process of soil material depends on bifurcation and plastic flow rule has influence on

bifurcation occurrence.

Though research on bifurcation phenomenon with associate flow rule has limitation of accuracy of

dynamic behavior, we have used this style in general.

So it is necessary to consider non-associate flow rule that is more accurate.

But, influence on bifurcation with new one has not known way to analysis for non-symmetric stiffness

matrix that has not established needs.

In this study, as substitution analysis, parabifurcation analysis to estimate a perfect

bifurcation behavior and to compare with each result from two flow rules.

In consequence, the larger initial irregularity, the smaller axis load becomes and

this degree is different from each initial irregularity.

Development of localization with non-associate flow rule is more remarkable.

Through all cases, estimated perfect bifurcation load with associate flow rule is larger than

one with non-associate.