A finite deformation multiplicative plasticity model with non–local hardening for bonded geomaterials

The paper presents a finite deformation, isotropic hardening, non–associative elastic–plastic constitutive model ( FD _ Milan model) for describing the mechanical behavior of wide range bonded natural geomaterials such as stiff overconsonsolidated clays, porous soft rocks or bio–improved soils. formulation is based on multiplicative split deformation gradient and assumption hyperelastic behavior. To deal with occurrence strain localization, typically observed in this class geomaterials, has been equipped non–local version hardening laws. This approach capable regularizing pathological mesh dependence occurring post–localization regime when adopting classical plasticity models. In view its application to practical geotechnical problems characterized by large displacements deformations within hydro-mechanical coupled environment, implemented recently developed Particle Finite Element code G–PFEM geomechanics applications. demonstrate effectiveness numerical implementation, series simulations performed considering two representative boundary value problems: modeling shear localization plane biaxial tests simulation CPTu saturated soil. results test have highlighted role characteristic length controlling thickness localized zone effect confining pressure determining pattern band formation. An interesting feature emerging from partially drained progressive formation persistent bands, which originate cone tip propagate outwards along entire penetration depth.