SUMMARY Theoretical analyses are made of the influence of the following features on the longitudinal shear and transverse tensile moduli of unidirectional fibre reinforced composites: (i) random variations in positioning of individual fibres, (ii) overall variations leading to fibre bunching, (iii) overall variations leading to interspersed matrix layers, (iv) localised variations resulting in ...

Lattice energies ΔLHθ of lanthanide orthophosphates, LnPO4 (Ln=Ce-Lu, excluding Pm) have been determined from the Born-Haber cycle and compared with those calculated by other methods. The Born-Haber cycle results in close values of ΔLHθ to those obtained after an empirical equation proposed by Glasser and Jenkins. It has been found that: (i) the partial derivative of the lattice enthalpies to t...

We calculate the shear modulus of crystalline color superconducting quark matter, showing that this phase of dense, but not asymptotically dense, three-flavor quark matter responds to shear stress like a very rigid solid. To evaluate the shear modulus, we derive the low energy effective Lagrangian that describes the phonons that originate from the spontaneous breaking of translation invariance ...

We present a non-destructive approach to sense inclusion objects embedded in a solid medium remotely from force sensors applied to the medium and boundary displacements that could be measured via a digital image correlation system using a set of cameras. We provide a rationale and strategy to uniquely identify the heterogeneous sample composition based on stiffness (here, shear modulus) maps. T...

Cellular solids are known to exhibit size effects, i.e., differences in the apparent effective elastic moduli, when specimen becomes comparable cell size. The present contribution employs direct numerical simulations (DNS) of mesostructure investigate influences porosity, shape pores, and thus material distribution along struts, orientation loading on effects moduli regular honeycomb structures...

OBJECTIVE This study aimed to evaluate and compare the mechanical properties of five commercial core materials using fracture toughness (FT), Knoop hardness number (KHN), diametral tensile strength (DTS), and dynamic elastic moduli (DEM). METHODS Composite material specimens were produced (Rock Core, CosmeCore, ParaCore, MultiCore Flow, and Filtek Supreme Plus). The FT test (n = 15) was perfo...

The linear-response effective shear moduli of polymer melts confined between strongly adsorbing surfaces (parallel plates of mica) was studied as a function of the excitation frequency. Linear response (achieved with shear amplitudes of e 2 A) implies that measurements did not perturb the film structure. The measurements employed a surface forces apparatus modified for dynamic mechanical shear ...

We have developed a new technique to measure viscoelasticity in soft materials such as polymer solutions, by monitoring thermal fluctuations of embedded probe particles using laser interferometry in a microscope. Interferometry allows us to obtain power spectra of fluctuating beads from 0.1 Hz to 20 kHz, and with subnanometer spatial resolution. Using linear response theory, we determined the f...

[1] Room temperature investigations on the shear strength, elastic moduli, elastic anisotropy, and deformation mechanisms of MgO (periclase) are performed in situ up to pressures of 47 GPa using radial X-ray diffraction and the diamond anvil cell. The calculated elastic moduli are in agreement with previous Brillouin spectroscopy studies. The uniaxial stress component in the polycrystalline MgO...

Experiments on isotropic compression of a granular assembly of spheres show that the shear and bulk moduli vary with the confining pressure faster than the 1/3 power law predicted by Hertz-Mindlin effective medium theories of contact elasticity. Moreover, the ratio between the moduli is found to be larger than the prediction of the elastic theory by a constant value. The understanding of these ...