Classical concepts of mechanics applied to continuous materials cannot be used directly for associations of soil clods occurring in ploughed and harrowed topsoils. Therefore, we are proposing a new simpli®ed method for analysing the clod : clod mechanics, for a wide range of clay content. We pressed together axially two adherent remoulded soil balls and recorded a dimensionless strain ̄attening...

purpose: to evaluate the effect of childhood corneal opacity on the anteroposterior length of the globe in adulthood. methods: twenty-three patients with significant unilateral corneal opacity which had developed before the age of 6 years and the normal fellow eyes (controls) were evaluated. a comprehensive ocular examination including measurement of anterioposterior length and anterior chamber...

The passive mechanical properties of blood vessel mainly stem from the interaction of collagen and elastin fibers, but vessel constriction is attributed to smooth muscle cell (SMC) contraction. Although the passive properties of coronary arteries have been well characterized, the active biaxial stress-strain relationship is not known. Here, we carry out biaxial (inflation and axial extension) m...

A local constitutive model for anisotropic granular materials is introduced and applied to isobaric (homogeneous) axial-symmetric deformation. The simplified model (in the coordinate system of the bi-axial box) involves only scalar values for hydrostatic and shear stresses, for the volumetric and shear strains as well as for the new ingredient, the anisotropy modulus. The non-linear constitutiv...

The mechanical behavior of an ensemble of athermal fibers forming a nonbonded network subjected to triaxial compression is studied using a numerical model. The response exhibits a power law dependence of stress on the dilatation strain and hysteresis upon loading and unloading. A stable hysteresis loop results after the first loading and unloading cycle. In the early stages of compaction, strai...

Ahstraet-Axisymmetric deformations of a transversely isotropic, rigid/perfectly plastic target being penetrated by a long rigid cylindrical rod with an ellipsoidal nose have been analyzed. The deformations of the target appear steady to an observer situated at the penetrator nose tip. The contact between the target and the penetrator is assumed to be smooth. Computed results show that the defor...

Based on the small deflection beam theory, bending equation with axial tension of suspended pipe partially buried in the linear elastic soil is established. And the corresponding boundary conditions are given according to the stress and deformation characteristics of suspended section and buried section. Then deflection equation for the suspended section is deduced. Afterwards, the stress and c...

We report calculated elastic tensors, axial Grüneisen parameters, and thermal stress distributions in Al2Mo3O12, ZrMgMo3O12, Sc2Mo3O12, and Y2Mo3O12, a series of isomorphic materials for which the coefficients of thermal expansion range from low-positive to negative. Thermal stress in polycrystalline materials arises from interactions between thermal expansion and mechanical properties, and bot...

We study the effects of the axial component of the shear stress on unsteady pipeline flows. We show that the axial component of the shear stress should be introduced in the modeling of unsteady flows, and as a numerical model, we propose a one-dimensional momentum equation in which a term containing the second derivative of the velocity with respect to space is introduced. The momentum equation...

Heart attack and stroke are often caused by atherosclerotic plaque rupture, which happens without warning most of the time. Magnetic resonance imaging (MRI)-based atherosclerotic plaque models with fluid-structure interactions (FSIs) have been introduced to perform flow and stress/strain analysis and identify possible mechanical and morphological indices for accurate plaque vulnerability assess...