β Scribed by Kenneth Runesson
No coin nor oath required. For personal study only.
The stress solution in plasticity with an associated or a non-associated flow rule is considered. Upon fully implicit integration of the relevant constitutive relations the stress is obtained as the projection of the (fictitious) elastic stress onto the yield surface for given values of the hardening/softening variables. This projection is defined, for a general non-associated flow rule, in adjusted complementary elastic energy, which becomes exactly the complementary energy when the flow rule is associated.
Isotropic elasticity and mean-stress dependent isotropic yield criteria (pertinent to soil) are considered and the implications of a certain class of non-associated flow rules are evaluated. This class relates to dilatant (or contractant) materials and involves non-associated plastic volume change. The corresponding stress solutions are shown to be strongly influenced by Poisson's ratio and by the dilation angle.
π SIMILAR VOLUMES
A two-phase coupled elastoplastic-damage model proposed by Ortiz (Ortiz M. Mechanics of Materials 1985;4:67Β± 93) for modeling inelastic behavior of concrete is considered. For integration of anisotropic damage evolution equations an implicit integration scheme is proposed and the resulting nonlinear
Constitutive relations in elastoplasticity may be formulated in a variety of ways, and different update algorithms may be employed to solve the resulting equations. Several implicit integration schemes, although some not widely used, have been suggested in the last years. Among them, the closest poi
This article is largely based upon the work conducted during the last six years by the writer while he was connected with the Michigan and Iowa Agricultural Experiment Stations.] UP to a few years ago the generally-accepted idea was that humus is made up of but a few organic compounds, chiefly acid