Launched before the atomic hypothesis took hold, elasticity theory is a spectacular achievement. A continuum-level description, it provides a powerful toolkit for determining how architecturally simple solids such as crystals respond macroscopically to stress, whilst encoding microscopic, atomic-realm details parsimoniously, via a few parameters. Solids that are architecturally complex at the a...

Strain gradient elasticity and nonlocal are two enhanced elastic theories intensively used over the last fifty years to explain static dynamic phenomena that classical fails do. The theory has a clear differentiation from case by considering stresses at point of continuum as an integral defined in treated body. On other hand, strain is characterized non-classical because considers both potentia...

This paper surveys some recent connections between classical invariant theory and the calculus of variations, stemming from the mathematical theory of elasticity. Particular problems to be treated include the equivalence problem for binary forms, covari-ants of biforms, canonical forms for quadratic variational problems, and the equivalence problem for particle Lagrangians. It is shown how thes...

Several models within the framework of continuum mechanics have been proposed over years to solve free vibration problem micro beams. Foremost amongst these are those based on non-local elasticity, classical couple stress, gradient elasticity and modified stress theories. Many retain basic features Bernoulli–Euler or Timoshenko–Ehrenfest theories, but they introduce one more material scale leng...

Strong local minimizers with surfaces of gradient discontinuity appear in variational problems when the energy density function is not rank-one convex. In this paper we show that stability of such surfaces is related to stability outside the surface via a single jump relation that can be regarded as interchange stability condition. Although this relation appears in the setting of equilibrium el...

We present a simplified one-dimensional model for pulse wave propagation through fluid-filled tubes with elastic walls, which takes into account the elasticity of the wall as well as the tapering effect. The spatial dynamics in this model is governed by a variable coefficient KdV equation with conditions given at the inflow site. We discuss an existence theory for the associated evolution equat...

We give an overview on existence results in nonlinear peridynamics, a nonlocal elasticity theory, and compare these results with those known for classical nonlinear elastodynamics. In peridynamics, it is possible to obtain stronger results under equal or even less restrictive assumptions on the stress.

The question is examined, whether the formally straightforward extension of Hooke’s time-honoured stress-strain relation to the four dimensions of special and of general relativity can make physical sense. The four-dimensional Hooke’s law is found able to account for the inertia of matter; in the flat space, slow motion approximation the field equations for the “displacement” four-vector field ...

1. Preliminary Remarks.-The condition of incompressibility used in our preceding note' in these PROCEEDINGS will now be replaced by the condition of the classical elasticity theory relating the divergence of the displacement vector and the mean stress. This leads to the usual form of theIHencky stress-strain relations for small plastic displacements which, for purposes of reference, we shall wr...

Coiled carbon nanotubes were produced catalytically by thermal decomposition of hydrocarbon gas. After deposition on a silicon substrate, the three-dimensional structure of the helix-shaped multiwalled nanotubes can be visualized with atomic force microscopy. Helical structures of both chiralities are present in the nanotube deposits. For larger coil diameters ( >170 nm), force modulation micro...