Ricardo A. Lebensohn

Learn More
-We present in this work a visco-plastic self-consistent (VPSC) anisotropic approach for modeling the plastic deformation of polycrystals, together with a thorough discussion of the assumptions involved and the range of application of such approach. We use the VPSC model for predicting texture development during rolling and axisymmetric deformation of(More)
We present the infinitesimal-strain version of a formulation based on fast Fourier transforms (FFT) for the prediction of micromechanical fields in polycrystals deforming in the elasto-viscoplastic (EVP) regime. This EVP extension of the model originally proposed by Moulinec and Suquet to compute the local and effective mechanical behavior of a(More)
An efficient full-field formulation based on fast Fourier transforms (FFTs) for the prediction of the viscoplastic deformation of polycrystals is applied to the study of the subgrain texture and microstructure evolution in polycrystalline Cu deformed under tension. Direct input from orientation imaging microscopy (OIM) images is used in the construction of(More)
We present here an extension of the viscoplastic self-consistent (VPSC) polycrystal model for the calculation of the intergranular Cauchy stresses in an aggregate. This method, which is based on the self-consistent treatment of incompressible aggregates proposed in 1987 by Molinari et al, is formulated using the inclusion formalism and full anisotropy is(More)
Interpretation of the massive amount of data (i.e,. microstructure images comprising millions of voxels) produced by emerging three-dimensional (3-D) characterization methods of polycrystalline materials, require very effi cient models. Such models should be able to use direct input from those images to predict mechanical response. In this work we present a(More)
The flow of glaciers and polar ice sheets is controlled by the highly anisotropic rheology of ice crystals that have hexagonal symmetry (ice lh). To improve our knowledge of ice sheet dynamics, it is necessary to understand how dynamic recrystallization (DRX) controls ice microstructures and rheology at different boundary conditions that range from pure(More)
The viscoplastic deformation of polycrystals under uniaxial loading is investigated to determine the relationship between hot spots in stress and their location in relation to the microstructure. A 3D full-field formulation based on fast Fourier transforms for the prediction of the viscoplastic deformation of poly-crystals is used with rate-sensitive(More)
We propose an extension of the model by Yoshida et al. (1996), where deformation in the inner core is forced by preferential growth in the equatorial belt, by taking into account the presence of a stable compositional stratification. Stratification inhibits vertical motion, imposes a flow parallel to isodensity surfaces, and concentrates most deformation in(More)
Elastic anisotropy of sheet-silicate-rich rocks such as shales and slates strongly depends on the orientation distribution of platelet-shaped minerals, as well as shape and orientation of pores. Bulk elastic anisotropy of the rock results in the anisotropy with respect to the propagation of elastic waves, and consequently, the fastest P-waves can travel(More)
An elastic-viscoplastic model for describing the anisotropic high-strain rate behavior of both low-symmetry and high-symmetry textured materials is proposed. Yielding is described using a recently developed criterion which can capture simultaneously anisotropy and compression– tension asymmetry associated with deformation twinning. The anisotropy(More)