in this work, an inverse finite element formulation was modified for considering material anisotropy in obtaining blank shape and forming severity of deep drawn orthotropic parts. in this procedure, geometry of final part and thickness of initial blank sheet were known. after applying ideal forming formulations between material points of initial blank and final shape, an equation system was obt...

We consider a fluid model including viscoelastic and viscoplastic effects. The state is given by the velocity an internal stress tensor that transported along flow with Zaremba-Jaumann derivative. Moreover, obeys nonlinear nonsmooth dissipation law as well diffusion. prove existence of global-in-time weak solutions satisfying energy inequality under general Dirichlet conditions for field Neuman...

We study a numerical method for the simulation of free surface flows of viscoplastic (Herschel-Bulkley) fluids. The approach is based on the level set method for capturing the free surface evolution and on locally refined and dynamically adapted octree cartesian staggered grids for the discretization of fluid and level set equations. We consider an extension of the stable approximation of the N...

Plastic flow localization in porous elastic-viscoplastic solids is analyzed with an emphasis on the effects of material rate sensitivity and plastic potential surface curvature. The effect of rate sensitivity is included in a material model that accounts for a change of yield surface curvature in a rate-insensitive porous ductile solid. Shear band formation under plane strain and axisymmetric t...

An asymptotic model is constructed to describe the bending of thin sheets, or plates, viscoplastic fluid described by Herschel–Bulkley constitutive law, which incorporates von Mises yield condition and a nonlinear viscous stress. The reduces number previous ones from plasticity theory mechanics in various limits. It characterized criterion proposed Ilyushin compactly combines effect moment in-p...

The time-independent and time-dependent mechanical behavior of electrochemically lithiated silicon was studied with nanoindentation. As indentation was performed with continuous stiffness measurements during loading and load-hold, new insight into the deformation behavior of lithiated silicon is furnished. Supporting other research, Young's modulus and the hardness of lithiated silicon are foun...