Certain Goals of Calculating the Power of Plastic Deformation of Powder Metal Systems
The approach to the construction of upper and lower estimates of the power of plastic deformation taking into account the plastic dilatancy of the material of powder metal systems (powders of metals, steels, color alloys - typical representatives of dilatant media) is considered. For the upper bound, the main relations of the plasticity theory of rigid-plastic isotropic dilatation media are written out. A functional is constructed that is an upper estimate of the plastic deformation capacity of the dilatating medium in a volume with a finite number of discontinuity surfaces considered to be stationary. For a lower bound, a statically admissible approximating stress distribution is given and a lower estimate of the power of the surface forces at given velocities is found. On the basis of the plastic potential, solutions are constructed for the upper and lower estimates of the power of plastic deformation. An example of calculation of steady plastic flow is considered when extruding a strip through a plane matrix. Based on the results of the research, a system of equations is formulated that can be used to find the boundaries of plastic zones, stresses and lower estimates of the force and power of plastic deformation.