Seismic analyses of methane hydrate data from the Blake Outer Ridge indicate high Pwave velocity and anomalously low S-wave velocity in sediments containing methane hydrates. In an attempt to explain this observed P-wave and S-wave velocity structure at the transition from gas to hydrates, the effect of different hydrate models on elastic moduli and velocities are explored. After construction o...

To characterize tissues in atherosclerotic plaques, we have developed a method, the phased tracking method, for measuring the strain (change in wall thickness) and elasticity of the arterial wall. However, some types of tissue, such as lipids and blood clots, cannot be discriminated from each other based only on elasticity due to the small difference in their elasticity. For more precise tissue...

Makishima and Mackenzie model was used to simulation of acoustic properties (longitudinal and shear ultrasonic wave velocities, elastic moduli theoretically for many tellurite and borate glasses. The model was proposed mainly depending on the values of the experimentally measured density, which are obtained before. In this search work, we are trying to obtain the values of densities of amorphou...

BEl-rt's reciprocal theorem is used to determine the normal displacements due to a normal point force at the plane surface o fa generally-anisotropic half-space or a transversely-isotropic general elastic foundation, using a state of plane sinusoidal loading as auxiliary solution. The method is also extended to give a dual integral equation formulation of the axisymmetric contact problem for an...

The elastic moduli of polymer-carbon nanotube composites are examined by molecular dynamics simulations of a single-walled carbon nanotube embedded in polyethylene. The overall system is modeled with a many-body bond order potential due to Brenner. Alternatively, only the carbon nanotube is modeled with Brenner’s potential and the polyethylene matrix is modeled by a united-atom potential. For t...

The complete set of elastic stiffness coefficients of a single crystal of Mg,SiO, in the modified spine1 (wadsleyite) structure are reported at eight pressures from ambient to 14 Gigapascals (GPa). All moduli vary linearly with pressure within the resolution of the data. Third-order Birch-Mumaghan equation fits to aggregate elastic moduli yield values of 170 (k 2) GPa and 4.3 (k 0.2) for the ad...

Gels formed by semiflexible filaments such as most biopolymers exhibit non-linear behavior in their response to shear deformation, e.g., with a pronounced strain stiffening and negative normal stress. These negative normal stresses suggest that networks would collapse axially when subject to shear stress. This coupling of axial and shear deformations can have particularly important consequences...

We address the interesting temperature range of a glass forming system where the mechanical properties are intermediate between those of a liquid and a solid. We employ an efficient Monte Carlo method to calculate the elastic moduli, and show that in this range of temperatures the moduli are finite for short times and vanish for long times, where short and long depend on the temperature. By inv...

In this article, surface stress and nonlocal effects on the biaxial and uniaxial buckling of rectangular silver nanoplates embedded in elastic media are investigated using finite difference method (FDM). The uniform temperature change is utilized to study thermal effect. The surface energy effects are taken into account using the Gurtin-Murdoch’s theory. Using the principle of virtual work, the...

The general theory for small dynamic motion superimposed upon large static deformation, or acoustoelasticity, is developed for isotropic fluid-filled poroelastic solids. Formulas are obtained for the change in acoustic wave speeds for arbitrary loading, both on the frame and the pore fluid. Specific experiments are proposed to find the complete set of third-order elastic moduli for an isotropic...