In X-ray interference fringes accompanied by mirage diffraction, variations have been observed in the spacing and position of the fringes from a plane-parallel Si single crystal fixed at one end as a function of distance from the incident plane of the X-rays to the free crystal end. The variations can be explained by distortion of the sample crystal due to gravity. From the variations and posit...

The construction of regularization operators presented in this work is based on the introduction of strain or damage micromorphic degrees of freedom in addition to the displacement vector and of their gradients into the Helmholtz free energy function of the constitutive material model. The combination of a new balance equation for generalized stresses and of the micromorphic constitutive equati...

Abstract The literature in the field of higher-order homogenization is mainly focused on 2-D models aimed at composite materials, while it lacks a comprehensive model targeting 3-D lattice materials (with void being inclusion) with complex cell topologies. For that, computational scheme based Mindlin (type II) strain gradient elasticity theory developed here. variational formulation periodic bo...

This paper concerns the behavior of hyperelastic energies depending on an internal parameter. First, the situation in which the internal parameter is a function of the gradient of the deformation is presented. Second, two models where the parameter describes the activation of skeletal muscle tissue are analyzed. In those models, the activation parameter depends on the strain and it is important...

Abstract We propose a phase-field theory for enriched continua. To generalize classical models, we derive the gradient based on balances of microforces, microtorques, and mass. focus materials where second gradients phase field describe long-range interactions. By considering nontrivial interaction inside body, described by boundary-edge microtraction, characterize existence hypermicrotraction ...

For very shallow indentations in W, Al, Au, and Fe-3wt%Si single crystals, hardness decreased with increasing depth irrespective of increasing or decreasing strain gradients. As such, strain gradient theory appears insufficient to explain the indentation size effect (ISE) at depths less than several hundred nanometers. Present research links the ISE to a ratio between the energy of newly create...

The phonon dispersion relations calculated by atomic model: shell model and ab initio, and by microcontinuum theory are introduced in this paper. It is found that both atomic models and microcontinuum theory can describe the common feature of phonon dispersion relation for the crystal having more than one atom per primitive cell and can give a good fit to the experimentally measured data. The o...