течение

Research into the time-depended transactional processes in viscoplastic fluids

Authors: Safronchik M. I., Safronchik A. I.

The paper presents problem of transition from one steady-state conditions of viscoplastic fluid flow to another between parallel planes. The problem definition is given within the limits of five- parameter model, which permits to take up differences between behavior under stress and without stress and possible slippage along the solid walls. Hysteresis of deformation is considered by means of model of smooth transition from adhesion to slippage. The solution is determined by method of momentary eigenfunctions of Melamed-Grinberg.

Instantaneously not Elongated Directors in Three-Dimensional Kinematics of the Coulomb – Mohr Medium

Authors: Radaev Y. N.

Three-dimensional flows of perfectly plastic medium are considered within the framework of the Coulomb -- Mohr continuum model. The model is to be used in applied problems related to limit states and flows of sands, rocks and any other kind of granular media. The present study is based on a notion of asymptotic directions of the stress tensor and the strain tensor increment and as well on instantaneously not elongated directors which are orthogonal to the asymptotic directions and lie in the plane normal to the intermediate principal stress axis.