REGULARITIES OF CHANGE IN VOLUME STRESSES IN POLYCRYSTALLINE MATERIALS WITH A CUBIC LATTICE

Abstract

According to this model, the failure conditions of polycrystalline materials can be described under total load using simple strength criteria at the local level: maximum normal stress/strain. To describe the regularities of changes in volume stresses in polycrystalline materials with a volume lattice, nonlinear equations of connection between micro and macro states are used. It is shown that, within the framework of nonlinear coupling equations, fluctuations of volume stresses occur even under pure macroscopic shear. The limit of volume stress variation is commensurate with the macroscopic modulus of the stress/strain deviator and depends only on the crystal anisotropy coefficient. Based on the established regularities, a number of experimental thermomechanical effects can be explained, for example, energy dissipation associated with the concept of internal friction