I planned to tensile some nanowire (whose cross section is in 'circular’ shape).
This nanowire is put in the center of a large vacuum box.
I used following commands,but after several percent of strain, the cross section apparently becomes elliptical shape? I am doubting whether it is physically reasonable.
Interesting! how big is the strain? Remember that at very small size for certain orientation <100> and <110>, phase change or reorientaion in conjunction with shape changes in the nanowire will occur under their own surface stress and external stress. But for other orientations, the shape change due to deformation seems surpprising to me. So it depends.
check out our recent paper:
“Sample shape and temperature strongly influence the yield strenght of metallic nanopillars”, A. Cao, E. Ma, Acta Materialia, 56, 4816-4828 (2008).
If you have problem downloading it, I will email you a copy.
Best,
AC
If you're not constraining the xy geometry and it becomes elliptical, then
it must want to be elliptical. So forcing it to be circular would
not be a good thing.
Steve
Why do the circular nanowires tend to be elliptical? because they tend to reconstruct the surface to reduce the surface energy? This is true for extremely small wires. But as long as he said it is of circular shape, I guess, the size should above 2 nm. At that scale or above, the energy barrier for the surface reorientation should be big at room temperature.
Javis, let me know your results (figures) if you want.
Best,
AC