dynamic recrystallization, drx, behaviour of a precipitation hardened, ph, stainless steel was studied in connection with microstructural developments in a compression test. the experimental results showed that the dominant mechanism of softening is drx, but at high strain rates and low temperatures, ie, high zener-holman parameter, z, work hardening and dynamic recovery, drv, produced a pancke...

Natural ageing responses of duplex structured Mg-6%Li and Mg-6%Li-6%Zn-1.2%Y alloys have been investigated. Microstructural analyses revealed that the precipitation and coarsening process of α-Mg particles could occur in β-Li phases of both two alloys during ageing process. Since a certain amount of Mg atoms in β-Li phases were consumed for the precipitation of abundant tiny MgLiZn particles, t...

We report the results of observations of the black hole binaries XTE J1550−564 and H 1743−322 in their quiescent state using the Chandra X-ray Observatory. Both sources are detected at their faintest level of X-ray emission ever observed with a 0.5–10 keV unabsorbed luminosity of 2 × 10 32 (d/5 kpc) 2 erg s −1 for XTE J1550−564 and 9 × 10 31 (d/8 kpc) 2 erg s −1 for H 1743−322. These luminositi...

A closed-form expression for shear band spacing in strain-hardening, strain-rate-hardening and thermally softening thermoviscoplastic materials is derived by studying the stability of a homogeneous solution of equations governing its simple shearing deformations. The wavelength of the perturbation that maximizes its initial growth rate is assumed to determine the shear band spacing, Ls: The dep...

A new plastic hinge integration method overcomes the problems with nonobjective response caused by strain-softening behavior in force-based beam–column finite elements. The integration method uses the common concept of a plastic hinge length in a numerically consistent manner. The method, derived from the Gauss–Radau quadrature rule, integrates deformations over specified plastic hinge lengths ...

We studied three-dimensional transient large coupled thermomechanical deformations of a polycarbonate (PC) plate with a through-the-thickness inhomogeneity at its centroid. The PC exhibits strain softening followed by strain hardening and its elastic moduli are taken to be functions of strain rate and temperature. The inhomogeneity is either a void or a region of initial temperature higher than...

The effect of intrinsic ripples on the mechanical response of the graphene monolayer is investigated under uniaxial loading using molecular dynamics (MD) simulations with a focus on nonlinear behavior at a small strain. The calculated stress-strain response shows a nonlinear relation through the entire range without constant slopes as a result of the competition between ripple softening and bon...