土質材料におけるせん断帯の形態予測

概要

論文の詳細を見る
The published theory of plasticity in soil is established in such a framework that the hardening modulus h vanishes when the volumetric compressive strain rate ε_p is zero. In general, soil shows dilatancy under relatively low pressure, where h is negative. This is called strain softening. On the other hand, it is proved theoretically that plastic instability arises at h=0. However, at ε_p≤0 plastic instability has not been generally observed in reality. We have developed a modified theory of plasticity in soil where the hardening properties of soil are made consistent with the expanding characteristics of the yield surface. As a result, the phenomenon of strain softening is eliminated in the theory. The velocity gradient is discontinuous on the necking plane forming a boundary between the shear band and its exteriors. On the other hand, a characteristic plane is the one beyond which solutions cannot be extended without additional information, because some of the derivatives normal to the plane cannot be determined using their governing equations alone. Therefore, on the characteristic plane, some derivatives of stress rates become indefinite and such a property must also be required for the necking plane. We examine the mode of the characteristic plane in a simple cap model. There are two modes, P and O. Mode O corresponds to the shear band mode arising in a plane strain compression test. Good agreement is obtained between the theory and the experiment by Vardoulakis when taking about 40 degree as the inclination angle in the Mohr-Coulomb criterion.
一般社団法人日本機械学会の論文
1997-07-25

土質材料におけるせん断帯の形態予測

スポンサーリンク

概要

著者

関連論文

スポンサーリンク