A finite element simulation of stress evolution in thin metal film during electromigration is reported in this paper. The electromigration process is modeled by a coupled diffusionmechanical partial differential equations (PDEs). The PDEs are implemented with a plane strain formulation and numerically solved with the finite element (FE) method. The evolutions of hydrostatic stress, each compone...

Creep of the cement matrix affects structural stability concrete. In Portland cements, creep is largely controlled by binding phase calcium-(aluminum-)silicate-hydrate, or C-(A-)S-H. This has a lamellar structure and under deviatoric stress aligns its c -axis with principal stress. However, limiting resistance to this reorientation unknown at nanocrystalline level. Small-angle X-ray scattering ...

Finite Element (FE) head models are often used to understand mechanical response of the head and its contents during impact loading in the head. Current FE models do not account for non-linear viscoelastic material behavior of brain tissue. We developed a new non-linear viscoelastic material model for brain tissue and implemented it in an explicit FE code. To obtain sufficient numerical accurac...

Recent seismic studies of ice stream B, Antarctica and field analysis of mid-latitude glacial deposits suggest that deformable basal sediments (e.g., water-saturated till) are important in determining ice sheet flow. If the ratio of till viscosity to effective ice viscosity is small, vertical shear associated with horizontal flow is confined to the deforming bed alone. Ice flow over a deformabl...

We propose a new method for carrying out field-theoretic simulations of polymer systems under conditions of prescribed external stress, allowing for shape changes in the simulation box. A compact expression for the deviatoric stress tensor is derived in terms of the chain propagator, and it is used to monitor changes in the box shape according to a simple relaxation scheme. The method allows fu...

This paper reexamines orientations of shear bands (fault angles) predicted by a theory of shear localization as a bifurcation from homogeneous deformation. In contrast to the Coulomb prediction, which does not depend on deviatoric stress state, the angle between the band normal and the least (most compressive) principal stress increases as the deviatoric stress state varies from axisymmetric co...

A local constitutive model for granular materials with anisotropy is proposed and applied to different biaxial box deformation modes. The simplified version of the model (in the coordinate system of the biaxial box) involves only scalar values for hydrostatic and shear stresses, for the isotropic and shear strains as well as the new parameter, the (scalar) anisotropy modulus. A non-linear const...

Stressand structure-anisotropy (bulk) responses to various deformation modes are studied for dense packings of linearly elastic, frictionless, polydisperse spheres in the (periodic) triaxial box element test configuration. The major goal is to formulate a guideline for the procedure of how to calibrate a theoretical model with discrete particle simulations of selected element tests and then to ...

Dry, frictional, steady-state granular flows down an inclined, rough surface are studied with discrete particle simulations. From this exemplary flow situation, macroscopic fields, consistent with the conservation laws of continuum theory, are obtained from microscopic data by time-averaging and spatial smoothing (coarse-graining). Two distinct coarse-graining length scale ranges are identified...