An assessment of the plasticity-induced crack-closure concept is made, in light of some of the questions that have been raised on the validity of the concept, and the assumptions that have been made concerning crack-tip damage below the crack-opening stress. The impact of using other crack-tip parameters, such as the cyclic crack-tip displacement, to model crack-growth rate behavior was studied...

human capital has always been of high importance in economic growth literature. in this regard, several studies have tried to explain the role of this variable via the use of different models. the present study, in line with the previous ones, going to estimate the share of human capital in iranian economy production from 1974 to 2011 within the framework of ozawa (1965) and lucas’s (1988) endo...

Elastic anticavitation is the phenomenon of a void in an elastic solid collapsing on itself. Under the action of mechanical loading alone typical materials do not admit anticavitation. We study the possibility of anticavitation as a consequence of an imposed differential growth. Working in the geometry of a spherical shell, we seek radial growth functions which cause the shell to deform to a so...

Using aMarx-oscillator standing-wave resonancemethod, we measuredthe internal friction &' of sintered titanium containing up to 26 volume-percent voids (c). The surprising &I-versus-c curve shape, an exponential increase, lead us to remeasure &I-versus-c by acoustic-resonance spectroscopy, which gave similar results. We hypothesized that both void shape and void size change with c. For the void...

Hysteresis loop curves are highly important for numerical simulations of materials deformation under cyclic loadings. The models mainly take account of only the tensile half of the stabilized cycle in hysteresis loop for identification of the constants which don’t vary with accumulation of plastic strain and strain range of the hysteresis loop. This approach may be quite erroneous particularly ...

The failure modes of flip chip solder joints under high electrical current density are studied experimentally. Three different failure modes are reported. Only one of the failure modes is caused by the combined effect of electromigration and thermomigration, where void nucleation and growth contribute to the ultimate failure of the module. The Ni under bump metallization–solder joint interface ...

The formation of plate tectonics from mantle convection necessarily requires nonlinear rheological behavior. Recent studies suggest that self-lubricating rheological mechanisms are most capable of generating plate-like motion out of fluid flows. The basic paradigm of self-lubrication is nominally derived from the feedback between viscous heating and Ž temperature-dependent viscosity. Here, we p...

Precipitates are closely related to ductile damage and dynamic recrystallization (DRX) in magnesium alloys. Using molecular dynamics simulation the embedded atomic method, competition between DRX stimulated by precipitate of alloys is investigated. The effects distribution dimensions on void nucleation, dislocation emission, growth, quantitatively discussed. It found that compared system with a...