Neohypoplasticity Revisited

This paper presents further improvements to the neohypoplasticity (NHP), a constitutive model for sand, which overcomes some shortcomings of widely used hypoplastic models. The novelties presented in this paper includes a new description of the additional dilatancy due to the structural variable and the introduction of a new state variable, denoted as
, to consider the small strain stiffness in case of a 1D loading reversal. They remove shortcomings of earlier versions of NHP. The new formulations are presented and the performance of NHP is validated with experimental data from Karlsruhe fine sand. Both monotonic and cyclic tests are simulated under drained and undrained conditions. The results demonstrate that the NHP accurately reproduces the observed behaviour in monotonic and cyclic experiments.