Steady state crack propagation produce substantial plastic strain gradients near the tip, which are accompanied by a high density of geometrically necessary dislocations and additional local strain hardening. Here, the objective is to study these gradient effects on Mode I toughness of a homogeneous rate-sensitive metal, using a higher order plasticity theory. Throughout, emphasis is on the tou...

The effect of fibre bundling on the effective transverse properties of unidirectional fibre composites has been investigated by way of finite element method and micromechanics models of fibre bundles. Based on the micromechanical model of single-fibre composites, plane strain models for composites reinforced by fibre bundles are presented. The effective elasto-plastic stress /strain behaviour w...

In nanocrystalline metals, lack of intragranular dislocation sources leads to plastic deformation mechanisms that substantially differ from those in coarse-grained metals. However, irrespective of grain size, plastic deformation is considered irrecoverable. We show experimentally that plastically deformed nanocrystalline aluminum and gold films with grain sizes of 65 nanometers and 50 nanometer...

An elastoplastic phase field model is developed to investigate the role of lateral confinement on morphology of thin films grown heteroepitaxially on patterned substrates. Parameters of the model are chosen to represent InxGa1-xAs thin films growing on GaAs patterned with SiO2. We determined the effect of misfit strain on morphology of thin films grown in 0.5μm patterns with non-uniform deposit...

Fifteen mechanochemical phenomena observed under compression and plastic shear of materials in a rotational diamond anvil cell (RDAC) are systematized. They are related to strain-induced structural changes (SCs) under high pressure, including phase transformations (PTs) and chemical reactions. A simple, three-scale continuum thermodynamic theory and closed-form solutions are developed which exp...

Fractal patterns are observed in computational mechanics of elastic-plastic transitions in two models of linear elastic/perfectly plastic random heterogeneous materials: (1) a composite made of locally isotropic grains with weak random fluctuations in elastic moduli and/or yield limits and (2) a polycrystal made of randomly oriented anisotropic grains. In each case, the spatial assignment of ma...

The changes in elastic lattice-strain profiles and plastic zone around the fatigue crack in a compact-tension specimen were investigated during monotonic tensile loading and unloading cycles using neutron diffraction. Spatially-resolved strain measurements were performed on a 316 LN stainless steel to determine the in-plane (parallel to the loading direction) lattice-strain profiles ahead of th...

This paper describes a new methodology for characterising the plastic zone ahead of fatigue crack. is applied to set experimental data obtained by synchrotron X-ray diffraction on bainitic steel compact tension specimen. The based generating equivalent Von Mises strain field from elastic maps. Based material response, threshold then maps identify size and shape zone. lies between plane stress W...