Ah&act-Steady state thermomechanical deformations of a thick viscoplastic target being penetrated by a fast moving long rigid cylindrical penetrator are analysed by the finite element method. Two different constitutive relations, the Bodner-Partom flow rule, and the Litonski-Batra flow rule, are used to model the viscoplastic response of the material. The two flow rules are calibrated to give e...

Using the periodic unfolding method we construct the homogenization theory for the quasistatic initial boundary value problems with internal variables, which model the deformation behavior of viscoplastic materials with a periodic microstructure. The free energy associated with models is assumed to be positive semi-definite only.

The following note shows that the symmetry of various resistance formulae, often based on Lorentz reciprocity for linearly viscous fluids, applies to a wide class of nonlinear viscoplastic fluids. This follows from Edelen's nonlinear generalization of the Onsager relation for the special case of strongly dissipative rheology, where constitutive equations are derivable from his dissipation poten...

This paper provides a short Matlab implementation with documentation of the P1 finite element method for the numerical solution of viscoplastic and elastoplastic evolution problems in 2D and 3D for von-Mises yield functions and Prandtl-Reuß flow rules. The material behaviour includes perfect plasticity as well as isotropic and kinematic hardening with or without a viscoplastic penalisation in a...

The creep problems are often involved in soil under cyclic loading, and its behaviors of loading sparks many arguments current research field. To propose one new model to demonstrate these the was simplified equivalently, elastic-viscoplastic (EVPM) for established based on Bingham model. yield criterion with constant amplitude proposed following load. A constitutive equation EVPM constructed b...

Purpose: The goal of this investigation was to characterize the compliance properties in selected polymers used for temporary (provisional crown and bridge) applications. Method: Polymethyl methacrylate (PMMA)- and polyethyl methacrylate (PEMA)-based JET and TRIM II were investigated along with two bisacryl composite resins (LUXATEMP and PROTEMP 3 GARANT). Rectangular samples of the resins were...

in this paper we have discussed the main features of a finite clement program which we have developed for nonlinear dynamic analysis of plates and shells with material and geometric nonlinear behaviour. for this purpose, initially, the finite element model which we have used is briefly described. afterwards, the nonlinear viscoplastic material model in one-dimensional and multi-dimensional medi...