An Elasto plastic Constitutive Model with Hardening softening Behavior for Sandy Soil Based on Modified plastic Work State Function

Abstract:

A new elasto plastic constitutive model for sand is proposed according to a stress path independent energy based hardening function.A stress path independent relationship between the irreversible strain energy and a stress parameter is formulated based on results from a series of drained plane strain compression (PSC) tests on saturated dense Toyoura sand with precise stress and strain measurements performed along a wide variety of stress path.The model is coupled with an isotropically work hardening and softening,non associated,elasto plastic material description.The FEM code incorporating the above mentioned model is validated by simulating physical PSC tests.The proposed model can better simulate the effects on the deformation characteristics of stress history as well as those of pressure level,inherent anisotropy,void ratio and work softening associated with strain localization into a shear band.

Key words:sandy soil; plane strain compression; constitutive model; stress path; hardening softening