In this paper, a self-consistent plasticity theory is proposed to model the mechanical behaviours of irradiated face-centred cubic nanocrystalline metals. At the grain level, a tensorial crystal model with both irradiation and grain size effects is applied for the grain interior (GI), whereas both grain boundary (GB) sliding with irradiation effect and GB diffusion are considered in modelling t...

In this work, dynamic mechanical properties of three high-manganese steels with TRIP/TWIP or fully TWIP characteristics are studied. High strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. All the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). Bu...

BACKGROUND Hardcore smokers are smokers who have smoked for many years and who do not intend to quit smoking. The "hardening hypothesis" states that light smokers are more likely to quit smoking than heavy smokers (such as hardcore smokers). Therefore, the prevalence of hardcore smoking among smokers would increase over time. If this is true, the smoking population would become harder to reach ...

BACKGROUND It has been argued that as smoking prevalence declines in countries, the smokers that remain include higher proportions of those who are unwilling or unable to quit (a process known as 'hardening'). Smokeless tobacco and e-cigarettes have been promoted as a strategy to deal with such smokers. If hardening is occurring, there would be a positive association between smoking prevalence ...

Surfaces play a key role during ferroelastic switching and define the interactions of materials with ionic species biological systems. Here, we perform molecular dynamics simulations identify ridges valleys rounded singularities around intersections between twin walls surfaces. Two dominant length scales stem from elastic bending surface layer (>30 lattice units) local atomic reshuffles ...

The direct parametrisation method for invariant manifolds is a nonlinear reduction technique which derives mappings and reduced-order dynamics that describe the evolution of dynamical systems along low-dimensional invariant-based span phase space. It can be directly applied to finite element problems. When development performed using an arbitrary order asymptotic expansion, it provides efficien...

Lead zirconate titanate (Pb(Zr1−xTix)O3 or PZT) ferroelectric ceramics have been widely used in transducers, actuators, and sensors, since they posses high dielectric and piezoelectric properties with a relatively high temperature of operation. Commercially used PZT ceramics are always modified by different dopants and are divided into the “soft” (donor doped) and “hard” (acceptor doped) groups...

The commonly employed mathematical functions in constitutive models, such as the strain hardening/softening model, strain-rate hardening factor, and temperature-softening are reviewed, their prediction characteristics illustrated. results may assist one (i) to better understand behavior of model that employs a given function; (ii) find reason for deficiencies, if any, an existing model; (iii) a...

dual phase steels with different martensite volume fraction and morphology were tensile tested at a temperature range of 25 to 5500c. stress-strain curves of all steels showed serration flow at temperatures of 250 and 3500c, and smooth flow at the other temperatures. both yield and ultimate tensile strengths increased with increasing testing temperature up to about 4500c and then decreased at h...