Abstract
Hypo-elasticity does not generally imply the existence of an elastic strain energy potential. However, it appears that for a hypo-elastic model describing inherent and stress state-induced anisotropy of uncemented granular materials, elastic strain energy can be stress path-independent. As a consequence, elastic strain energy represents a potential uniquely defining the direction of the elastic strain vector along stress paths with a constant stress ratio, which is confirmed by experimental data for some sands.
