The cold compaction of an aggregate of powder is treated from the viewpoint of crystal plasticity theory. The contacts between particles are treated as compaction planes which yield under both normal and shear straining. The hardening of each plane represents both geometric and material hardening at the contacts between particles; the macroscopic tangent stiffness can be written in terms of the...

In this paper, we propose an iterative beam hardening correction method that is applicable for the case with multiple materials. By assuming that the materials composing scanned object are known and that they are distinguishable by their linear attenuation coefficients at some given energy, the beam hardening correction problem is converted into a nonlinear system problem, which is then solved ...

This investigation provides a mechanistic background to mechanical property extractions performed from single-crystal microhardness measurements. The analysis concerns both spherical and sharp (pyramidal) indentations. We show that the uniaxial stress–strain curves inferred from hardness measurements in single crystalline units of material are coincidental with those attained under true uniaxia...

a r t i c l e i n f o Recent high-resolution GPS and seismological data reveal that tectonic faults exhibit complex, multi-mode slip behavior including earthquakes, creep events, slow and silent earthquakes, low-frequency events and earthquake afterslip. The physical processes responsible for this range of behavior and the mechanisms that dictate fault slip rate or rupture propagation velocity ...

High precision applications, such as, semiconductor manufacturing and diamond turning of optical elements require positioning accuracy within nanometers and therefore require very precise motion control of machine tool axes. The frictional behavior at the slides is a result of very complex interaction between the contacting surfaces and lubricants. No accurate quantitative prediction of the fri...

Abstract The mathematical description of the material behavior rock is a demanding task in engineering practice. Rock classified as frictional cohesive characterized by highly nonlinear mechanical with irreversible deformation, strain hardening, softening and degradation stiffness. In addition, depending on origin particular type, orientation minerals grains well formation stratification planes...

Continuing to fertilize bareroot and container seedlings during the hardening process (from cessation of height growth until lifting) can improve seedling viability. The process of fertilizing during hardening has many names, but in the last decade a new term, nutrient loading, has come into use. The process of nutrient loading seedlings leads to luxury consumption indicated by foliar nitrogen ...

Work hardening in crystalline materials is related to the accumulation of statistically stored dislocations in low-energy structures. We present here a model which includes dislocation dynamics in the rate-independent setting for plasticity. Three basic physical features are taken into account: (i) the role of dislocation densities in hardening; (ii) the relations between the slip velocities an...

We present novel results on flow properties using molecular dynamics simulation as well as γ -densitometry experiments. We show that fundamentally different types of granular flow can be observed in one unique system. Using both frictional and frictionless confining walls, we show that the differences existing between these regimes originate in the frictional properties of the walls. The salien...