We consider rate-independent models of static and quasistatic plasticity with hardening. These models are usually stated in terms of variational inequalities of the first or second kind, for the primal and dual formulations, respectively. In the static case, the dual variational inequality can be interpreted as the necessary and sufficient optimality conditions for an underlying optimization pr...

Abstract Block braked railway wheels are subjected to thermal and rolling contact loading. The loading results in high temperatures stresses which cause slow time dependent processes such as creep, relaxation static recovery of the wheel material. At same time, implies a very fast mechanical load application. This paper is focused on material modeling pearlitic steel for wide range rates at ele...

Hardening plasticity has a long history in constitutive modelling, with many applications in geomechanics. Mathematical models of non-hardening plasticity involve the definition of a single stationary yield surface in stress-space. Examples include the conventional models of elasto-plasticity, often based on the yield criteria of Tresca, von Mises, and Mohr-Coulomb. Within the yield surface the...

In this paper we consider an optimal control problem governed by a time-dependent variational inequality arising in quasistatic plasticity with linear kinematic hardening. We address certain continuity properties of the forward operator, which imply the existence of an optimal control. Moreover, a discretization in time is derived and we show that every local minimizer of the continuous problem...

High-attenuation object-induced streaking and shadow artifacts in computerized tomography (CT) are somewhat connected to the misfit of the X-ray projection data to the range space of the Radon transform. This misfit is mainly due to the beam hardening factor of the projection data which is unavoidable for polychromatic sources. The major difficulty in dealing with the beam hardening-induced str...

The current paper's goal is to investigate how dynamic interaction phenomena and material nonlinearities affect the behavior of a concrete gravity multi-arch dam in terms maximum displacements, natural stresses, principal Von Mises stresses when subjected seismic excitation. Utilizing ANSYS APDL software, linear nonlinear transient analysis using finite element method was employed analyze betwe...

A phenomenological constitutive law for ferroelectric switching due to multi-axial mechanical and electrical loading of a polycrystalline material is developed. The framework of the law is based on kinematic hardening plasticity theory and has a switching surface in the space of mechanical stress and electric field that determines when non-linear response is possible. The size and shape of the ...

Nonlinear analysis of anisotropic structures is described by using Hill’s yield criterion that anisotropic yield contour is assumed to be retained its shape during the hardening process. Nonlinear constitutive equation of anisotropic material is derived using plastic potential concept. Linear strain hardening model is utilized and forward Euler method is employed as a stress integration method....

Ratcheting behavior of steel 304L cylindrical shell under cyclic combined and axial loading are investigated in this paper, numerically. Cylindrical shells were fixed oblique at angle of 20° and normal with respect to the longitudinal direction of the shell and subjected to force-controlled cycling with non-zero mean force, which causes the accumulation of plastic deformation or ratcheting beha...