It is often found that tangent-stiffness finite element solutions for elastic-plastic materials exhibit much too stiff a response in the fully plastic range. This is most striking for the perfectly plastic material idealization, in which case a limit load exists within conventional small displacement gradient assumptions. However, finite element solutions often exceed the limit load by substant...

Severe plastic deformations under high pressure are used to produce nanostructured materials but were studied ex-situ. Rough diamond anvils introduced reach maximum friction equal yield strength in shear and the first in-situ study of evolution pressure-dependent radial distribution nanostructural parameters performed for severely pre-deformed Zr. ω-Zr behaves like perfectly plastic, isotropic,...

Microstructure evolutions in Ni-base superalloys are investigated during [110] creep loading using 3D and 2D phase field simulations. A recently developed model coupled to a crystal plasticity based on dislocation densities is employed. The uses storage-recovery law for the density of each glide system hardening matrix account short-range interactions between dislocations. We show that small mi...

The axisymmetric steady state deformations of an infinite cylindrical rod made of a rigid/perfectly plastic material and striking a known cavity in a rigid target are analyzed by the finite element method. The contact between the deforming rod and the target surface is assumed to be smooth. It is found that the axial force experienced by the rod depends strongly upon the square of its speed. Re...

This work reports a nonlithographic nanopatterning approach to fabricate perfectly ordered nanoparticle arrays with tunable and uniform dimensions from about 30 to 80 nm and strict periods of 100 nm in a square lattice on large-area substrates by combining nanoimprinting with ultrathin alumina membrane technique. There is no requirement of any organic layer to support an ultrathin membrane in o...