Hypoplasticity for Sand With Explicitly Defined Asymptotic States

ABSTRACT

A hypoplastic model for sand with defined asymptotic states is proposed. The fourth‐order tensor is defined by modifying the compression relation of the reference hypoplastic model by von Wolffersdorff (HP). This enables the mathematical formulation of a hypoplastic model for sand including the asymptotic state boundary surface (ASBS) using the ‐based mathematical framework.

The resulting asymptotic hypoplastic model (AHP) for sand can be formulated either using an implicitly defined ASBS (AHPi) or, based on the further proposed double formulation, using an explicitly defined ASBS (AHPe). Especially the AHPi reproduces the overall stress‐strain behavior of the reference HP model quite well. However, larger discrepancies occur between AHPe and HP, particularly for dense soils.

To further address cyclic loading effects, the AHP models are coupled with the generalized intergranular strain (GIS) concept. Element simulations confirm consistent responses of the HP+GIS model and the proposed constitutive formulations and demonstrate that the latter provides a basis for the future development of ASBS‐based hypoplastic models for sand.