A multiscale modeling methodology that combines the predictive capability of discrete dislocation plasticity and the computational efficiency of continuum crystal plasticity is developed. Single crystal configurations of different grain sizes modeled with periodic boundary conditions are analyzed using discrete dislocation plasticity (DD) to obtain grain size-dependent stress-strain predictions...

Thin fi lms with microcrystalline and nanocrystalline grains are used in MEMS and thin fi lms for electronics. These systems have mechanical properties that depend on the microstructure. Grain size is frequently reported only as mean values or bounds. It has been demonstrated, however, that a mean grain size value is insuffi cient to describe the microstructure of these materials and the result...

Nanocrystalline materials show a higher strain-rate sensitivity in contrast to the conventional coarse-grained materials and a different grain size dependency. To explain these phenomenon, a finite element model is constructed that considers both grain interior and grain boundary deformation of nanocrystalline materials. The model consist of several crystalline cores with different orientations...

Nanocrystalline (NC) metals with grain sizes <100 nm have attracted a lot of attention in the materials science fi eld for more than a few decades because of their ultra-high strength and hardness. Various experimental and computational studies indicate that dislocation-mediated plasticity prevails in NC metals when the grain size is larger than ~10 nm. Recent molecular dynamics (MD) simulation...

Methods A rate-dependent single crystal plasticity based algorithm is used for the three dimensional analysis of themechanical behaviour of ultra-thin specimens containing flat grains. The specimens are loaded in uniaxial tension. By analyzing the interaction of a single-crystalline matrix with a misoriented grain in the sheet samples, clear insight is obtained in the locally occurring grain–gr...

A significant contribution to the overall mechanical behaviour of microstructural materials is provided by the interaction of dislocation movement and grain boundaries. As a consequence, polycrystals are observed to respond with a higher strength for smaller grain sizes, a phenomenon which can not be modeled with classical single crystal plasticity theories. Gradient plasticity theories have be...

Size-affected dislocation-mediated plasticity is important in a wide range of materials and technologies. Here we develop a generalized size-dependent dislocation-based model that predicts strength as a function of crystal/grain size and the dislocation density. Three-dimensional (3D) discrete dislocation dynamics (DDD) simulations reveal the existence of a well-defined relationship between str...

This work investigates the microstructure-property linkages in magnesium (Mg) with an emphasis on understanding interaction effects between grain size, texture, and loading orientation. A single crystal plasticity framework endowed experimentally informed micro Hall-Petch type relations for activation thresholds slip twinning is adopted to resolve polycrystalline microstructures over a broad te...