Ilyushin’s Trace of Delay in Complex Loading of Granular Media with Continuous Rotation of Principal Axes of Strains

The authors performed a series of DEM-based numerical experiments connected with complex loading of a granular medium with continuous rotation of the principal axes of strains. The question of a trace of delay in the scalar and vector properties in the medium by Ilyushin is discussed. On the authority of the dilatancy analysis, the delay trace is calculated for the scalar properties of the granular medium. The delay in the vector properties is found in terms of the change in the directions of the principal axes of stresses, strains and strain rates during loading. The quantitative evaluations are given. It is found that the delay trace in granular media is one–two orders of magnitude higher than in metals.