Non-associative models in FLAC
N. Boukpeti, Andrew Drescher · 2020
Two non-associative elasto-plastic models based on the concepts of critical state, volumetric strain hardening and elliptical yield curve are considered. The models are implemented in FLAC using the FISH language. For comparison, also the modified Cam clay (associative) model and perfectly plastic Drucker-Prager model already embedded in FLAC are considered. The parameters of the models are determined from a drained triaxial test. The plane-strain punch indentation into a ponderable dry soil is simulated to assess the difference in model response. The hardening/softening models yield similar overall response, with the same limit load as the non-associative Dracker-Prager model; however, the load-displacement response for the latter model is much softer. Also, the limit load for the Drucker-Prager model depends strongly on the dilatancy parameter.