Ri. Borja et C. Tamagnini, CAM-CLAY PLASTICITY PART III - EXTENSION OF THE INFINITESIMAL MODEL TO INCLUDE FINITE STRAINS, Computer methods in applied mechanics and engineering, 155(1-2), 1998, pp. 73-95
The infinitesimal version of the modified Cam-Clay model of critical s
tate soil mechanics is reformulated to include finite deformation effe
cts. Central to the formulation are the choice of a hardening law that
is appropriate for cases involving large plastic volumetric strains,
and the use of a class of two-invariant stored energy functions approp
riate for Cam-Clay-type models that includes, as special cases. the co
nstant elastic shear modulus approximation as well as the pressure-dep
endent shear modulus elastic model. The analytical model is cast withi
n the framework of finite deformation theory based on a multiplicative
decomposition of the deformation gradient. For the fully elasto-plast
ic case, return mapping is done implicitly in the space defined by the
invariants of the elastic logarithmic principal stretches, which requ
ires the solution at each stress point of no more than three simultane
ous non-linear equations. A finite element analysis of a strip footing
problem is presented to illustrate a prototype example where finite d
eformation effects significantly impact the predicted response. (C) 19
98 Elsevier Science S.A.