We performed ab initio calculations of the elastic constants of five flexible metal-organic frameworks (MOFs): MIL-53(Al), MIL-53(Ga), MIL-47, and the square and lozenge structures of DMOF-1. Tensorial analysis of the elastic constants reveals a highly anisotropic elastic behavior, some deformation directions exhibiting very low Young's modulus and shear modulus. This anisotropy can reach a 400...

– We consider a simple model of a random heteropolymer chain that is known to undergo the freezing transition. We investigate the change in the elastic properties of the chain upon freezing. The elastic constants are evaluated and it is shown that they acquire a non-trivial contribution in the frozen phase. The goal of this letter is to investigate the elasticity of a random heteropolymer chain...

Carbon nanotubes (CNTs) possess extremely high stiffness, strength and resilience, and may provide the ultimate reinforcing material for the development of nanocomposites. Evaluating the effective elastic properties of such nanoscale materials is a difficult task. Modelings and simulations using continuum mechanics models can play significant roles in this development. In this paper, the nanost...

[1] Knowledge of the elastic properties and crystal chemistry of dense oxide structures plays an important role in interpreting the composition and mineralogy of planetary interiors. We report the effects of (Mg,Fe) substitution and nonstoichiometry due to Fe on the crystal structure, elastic constants (cij) and moduli (K0T, K0S, G0) of (Mg,Fe)O utilizing single-crystal X-ray diffraction and gi...

Elastic constants of two-dimensional (2D) colloidal crystals are determined by measuring strain fluctuations induced by Brownian motion of particles. Paramagnetic colloids confined to an air-water interface of a pendant drop are crystallized under the action of a magnetic field, which is applied perpendicular to the 2D layer. Using video microscopy and digital image processing we measure fluctu...

Ultrasonic attenuation due to phonon–phonon interaction and thermoelastic loss was evaluated in VIII group transition metal Pt in a wide temperature range (100 K to 1500 K) for longitudinal and shear waves along 〈100〉, 〈110〉 and 〈111〉 directions and for shear waves polarised along different directions. Electrostatic and Born–Mayer potentials were used to obtain second and third order elastic co...

The exoelectric e ect provides a linear coupling between electric polarization and orientational deformation in liquid crystals. It in uences many electrooptical phenomena and it is used in some bistable nematic devices. A statistical theory of dipole exoelectric polarization in biaxial nematic liquid crystals is used to calculate temperature dependence of order parameters, elastic constants, a...

Abstract The issue of how to find the best acoustical fit to a set of anisotropic elastic constants is addressed. The optimal moduli are determined which minimize the orientation averaged squared-norm of the difference in the acoustical tensors. The optimal moduli are derived explicitly and turn out to be identical to those obtained by minimizing the Euclidean distance function, or equivalently...

The issue of how to define and determine an optimal acoustical fit to a set of anisotropic elastic constants is addressed. The optimal moduli are defined as those which minimize the mean-squared difference in the acoustical tensors between the given moduli and all possible moduli of a chosen higher material symmetry. The solution is shown to be identical to minimizing a Euclidean distance funct...