INVESTIGADORES
MROGINSKI Javier Luis
congresos y reuniones científicas
Título:
A CONSISTENT GRADIENT-PLASTICITY FORMULATION FOR POROUS MEDIA BIFURCATION ANALYSIS
Autor/es:
JAVIER L. MROGINSKI; SONIA M. VRECH; GUILLERMO ETSE
Lugar:
Foz do Iguaçu, Paraná, Brazil
Reunión:
Congreso; 11th Pan-American Congress of Applied Mechanics - PACAM XI; 2010
Institución organizadora:
American Society of Civil Engineers (ASCE)
Resumen:
The strain localization problem of frictional cohesive materials is strongly related to the softening mechanical behavior and the instability phenomena in structural materials. In this situation a pathological dependences of the FE numerical solution is observed with respect to the size and orientation of the considered special discretization. This difficulty is mostly related to the strong dependence of the softening behavior in the post-peak regime on the boundary conditions in terms of the govern stress and hydraulic conditions. Thereby, the mathematical modeling of deformation behavior of porous media requires appropriate constitutive models in order to objectively describe their complex strength degradation processes under monotonic type of loading. In fact, these enhanced constitutive theories should be able to describe non local strain behaviors. In this work, a thermodynamically consistent gradient plasticity formulation is proposed in order to objectively model the deformation behavior and strain localization of frictional cohesive porous media, like soil or concrete. The non-local softening formulation of the proposed constitutive model incorporates the dependence of the gradient characteristic length on the governing stress and hydraulic conditions to realistically predict the size of the maximum energy dissipation zone. Firstly the basis of the thermodynamically consistent gradient plasticity theory is discussed. Then this theory is extended for the case of porous media like soils and particularly for the formulation of the non-local softening law. The localization tensor of the proposed non-local theory for porous media is obtained and the conditions for localized type of failure in uniaxial and triaxial compression tests are numerically evaluated.
