A scaling model is presented to analyze the reversible strain-hardening phenomenon in end-tethered polymer clay nanocomposites (Krishnamoorti, R.; Giannelis, E. P. Langmuir 2001, 17, 1448). It is assumed that for attractive clay-polymer interactions a fraction of the polymer chains that span the space between opposite clay plates get adsorbed on them, thereby bridging the plates. Under large am...

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

Microstructures and mechanical properties of equal-channel angular pressing (ECAP) processed and naturally aged ultrafine grained (UFG) and coarse grained (CG) 7075 Al alloys as well as their evolutions during annealing were investigated. After the same natural aging, the tensile yield strength, ultimate strength, and microhardness of the UFG samples were 103%, 35%, and 48% higher, respectively...

A well-known lower bound widely used in the massive MIMO literature hinges on channel hardening, i.e., the phenomenon for which, thanks to the large number of antennas, the effective channel coefficients resulting from beamforming tend to deterministic quantities. If the channel hardening effect does not hold sufficiently well, this bound may be quite far from the actual achievable rate. In rec...

Helium implantation at room temperature was performed to investigate irradiation hardening of ferritic/martensitic steels. Bulk hardness was extracted from Nix-Gao model using a Berkovich nano-indentor. The correlation between irradiation hardening and helium concentration ranging 500 2000 appm was examined. Nano-hardness increases as a function of helium concentration. The hardening of Fe is s...

A Fe-34.5 wt % Mn-0.04 wt % C ultra-high Mn steel with a fully recrystallised fine-grained structure was produced by cold rolling and subsequent annealing. The steel exhibited excellent cryogenic temperature properties with enhanced work hardening rate, high tensile strength, and high uniform elongation. In order to capture the unique mechanical behaviour, a constitutive model within finite str...

Introduction: One of the limitations of tissue conditioners (TC) is gradual hardening of the material in a short time period after insertion in the mouth, due to the loss of their viscoelastic properties. The aim of this study was to determine the softness of two different tissue conditioners with and without the Monopoly

as the turbine industries need to manufacture turbine blades made of martensitic stainless steel aisi 420 with high toughness and wear resistance, local laser hardening has become more and more important. in this research, surface of the samples was initially hardened by high-power pulsed laser beam; then, optimum parameters of hardening were calculated and wear resistance of surface hardened s...

Effects of the electrical flame off (EFO) parameters on the hardness and work hardening properties of Cu free air balls (FABs) are reported and compared to those of Au. Cu FABs were characterised using an online deformability method that measures the insitu deformability of the Cu FAB and by traditional off-line Vickers microhardness testing of cross-sectioned samples. The online deformability ...