Grain resolved information like this is vital for understanding what happens when the traditional continuum mechanics approach breaks down and fracture is governed by local heterogeneities (e.g. phase or stress differences) between grains.
For anisotropic metals, the distributions of the effective Schmid factors (ratios between the grain mean resolved shear stress computed either with or without neighboring grain effects and the macroscopic tensile stress) are strongly modified with respect to the reference distribution evaluated for isotropic elasticity.
Grain-resolving simulations based on the approach outlined here will provide a tool for further investigating the validity of the assumptions underlying the derivation of the μ(I) rheology.
Grain-resolving simulations of the type to be discussed in the following are expected to provide a tool for further investigating the validity of the assumptions underlying the derivation of the μ(I) rheology.
Atomistic simulations of the tensile deformation of three-dimensional nanocrystalline Al samples at constant strain rate and temperature are analyzed in terms of grain-averaged shear produced by dislocation slip and the grain-averaged resolved shear stress during deformation.
AC impedance spectra were involved to resolve grain interior and grain boundary resistance.
For resolving typical grain size, shape, and film homogeneity, scanning electron microscopy (SEM) was applied (eLine by Raith, secondary electron detector, accelerating voltage 10 kV, working distance 8 mm).
Similarly seismic attenuation, which is a strong function of grain size [ Karato, 2003], typically cannot resolve grain-size variations on the length-scales that are important for controlling ridge dynamics.
As Ray Villard, of the Space Telescope Science Institute, in Baltimore, wrote in an article that accompanied the image's release, "It's like photographing a beach and resolving individual grains of sand".
At a mere 2 million light-years away, Andromeda is the nearest spiral galaxy to our own, and the incredible detail of the image has allowed astronomers to see its individual stars for the first time a feat HubbleSite likens to resolving "individual grains of sand" in a photo of the beach.
"It's like photographing a beach and resolving individual grains of sand," says the NASA website's post accompanying the image release.
