At high pressure prevailing in the lower mantle, lattice friction opposed to dislocation glide becomes very high, as reported in recent experimental and theoretical studies. We examine the consequences of this high resistance to plastic shear exhibited by ringwoodite and bridgmanite on creep mechanisms under mantle conditions. To evaluate the consequences of this effect, we model dislocation cr...

The recurrence intervals of repeating earthquakes on the San Andreas Fault in the Loma Prieta aftershock zone follow the characteristic 1/t decay of Omori’s law. A model in which these earthquakes occur on isolated patches of the fault that fail in stick-slip with creep around them can explain this observation. In this model the recurrence interval is inversely proportional to the loading rate ...

Modern methodologies that aim to reduce conservatism in the design of components operating at high temperatures rely on accurate predictions of materials’ behaviour in conditions relevant to those experienced in service. This requirement has focussed the attention of materials engineers on developing a quantitative understanding of damage-accumulation in engineering alloys. The microstructure o...

Abstract-The validity of the parameter (AT), (which was previously introduced by one of the authors), its meaning, and its calculation, in the analysis of cracked bodies under non-steady creep conditions, are studied. Comparisons are made with the widely used parameter C*, which is valid for steady-state creep. An efficient finite element method for general, small-strain, elasticlviscoplastic a...

Creep polycrystalline ice samples antifreeze glycopeptides re-accelerating or tertiary samples. Previous work grain-boundary migration consistent with this, as nucleation and growth of curves containing (AFGPs) creep that has shown obtained from the low concentrations of do not show the is found in pure ice that AFGPs inhibit in ice and the present results are tertiary creep is associated with ...

Creep behavior of thick-walled functionally graded cylinder consisting of AlSiC and subjected to internal pressure and high temperature has been analyzed. The functional relationship between strain rate with stress can be described by the well known threshold stress based creep law with a stress exponent of five. The effect of imposing non-linear particle gradient on the distribution of creep s...

The previously developed microprestress-solidification theory for concrete creep and shrinkage is generalized for the effect of temperature ~not exceeding 100°C!. The solidification model separates the viscoelasticity of the solid constituent, the cement gel, from the chemical aging of material caused by solidification of cement and characterized by the growth of volume fraction of hydration pr...

The existence of multi-axial states of stress cannot be avoided in elevated temperature components. It is essential to understand the associated ailure mechanisms and to predict the lifetime in practice. Although metal creep has been studied for about 100 years, many problems are still nsolved, in particular for those involving multi-axial stresses. In this work, a state-of-the-art review of cr...

This paper presents results from a research initiative aimed at investigating high temperature creep deformation mechanisms in Ni-base superalloys through a combination of creep experiments, TEM deformation mechanism characterization, and state of the art modeling techniques. The effect of microstructure on dictating creep rate controlling deformation mechanisms was revealed for specimens with ...