Criterion of Plastic Instability.

Criterion for flow liquefaction instability

This study describes a general liquefaction flow instability criterion for elastoplastic soils based on the concept of loss of uniqueness. We apply the criterion to the general case of axisymmetric loading and invoke the concepts of effective stresses and loss of controllability to arrive at a general criterion for the onset of liquefaction flow. The criterion is used in conjunction with an ela...

plastic instability in equibiaxial deformation of sheet metals

plastic instability which results in the localization and failure of sheet metals has been studied in equibiaxial stretching of commercial purity aluminium sheet. attention was focussed on two main industrial conditions of the material. these were representative of the materials that could be processed by the commercial batchannealing process (slow heating, long time) or by a continuous anneali...

A Criterion for Nuclear-Energized Pulsational Instability

Richtmyer-Meshkov instability in elastic-plastic media.

An analytical model for the linear Richtmyer-Meshkov instability in solids under conditions of high-energy density is presented, in order to describe the evolution of small perturbations at the solid-vacuum interface. The model shows that plasticity determines the maximum perturbation amplitude and provides simple scaling laws for it as well as for the time when it is reached. After the maximum...

Atomistic basis for the plastic yield criterion of metallic glass.

Because of their disordered atomic structure, amorphous metals (termed metallic glasses) have fundamentally different deformation mechanisms compared with polycrystalline metals. These different mechanisms give metallic glasses high strength, but the extent to which they affect other macroscopic deformation properties is uncertain. For example, the nature of the plastic-yield criterion is a poi...