Multiscale Modeling of Large Strain Phenomena in Polycrystalline Metals

2010 ◽  
pp. 37-54
Author(s):  
Kaan Inal ◽  
Raj. K. Mishra
Keyword(s):  
Multiscale Modeling ◽  
Large Strain ◽  
Polycrystalline Metals

Multiscale Modeling and Simulation of Crystal Plasticity Based on Dislocation Patterning in Polycrystal

2007 ◽  
Vol 340-341 ◽  
pp. 205-210 ◽  
Author(s):  
Naoshi Yamaki ◽  
Yoshiteru Aoyagi ◽  
Kazuyuki Shizawa
Keyword(s):  
Modeling And Simulation ◽  
Multiscale Modeling ◽  
Crystal Plasticity ◽  
Stress Condition ◽  
Diffusion Theory ◽  
Large Strain ◽  
Cell Structure ◽  
Reaction Diffusion ◽  
Multiscale Model ◽  
Stress Effect

A multiscale model on dislocation patterning of cell structure and subgrain for polycrystal is newly developed on the basis of reaction-diffusion theory. A FD simulation for dislocation patterning and a FE one for crystal deformation are simultaneously carried out for a FCC polycrystal at large strain. Reflecting stress value on stress-effect coefficients, it is numerically predicted that the evolution of dislocation pattern in a polycrystal is different in response to the stress condition of each grain.

Multiscale modeling of transgranular short crack growth during fatigue in polycrystalline metals

2018 ◽  
Vol 116 ◽  
pp. 648-658 ◽  
Author(s):  
Jianxing Mao ◽  
Dianyin Hu ◽  
Fanchao Meng ◽  
Xiao Zhou ◽  
Jun Song ◽  
...  
Keyword(s):  
Crack Growth ◽  
Multiscale Modeling ◽  
Short Crack ◽  
Polycrystalline Metals

A TEM study of the microstructure of avian eggshells

1992 ◽  
Vol 50 (2) ◽  
pp. 1102-1103
Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Growth Mechanisms ◽  
Shell Surface ◽  
Thin Sections ◽  
Polycrystalline Metals ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.

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