The previously derived expressions for the incremental elastic coefficients of an isotropic medium under initial stress are applied to rubbertype elasticity. As a corollary an exact theory is obtained for the surface instability of such material under compression. It is found that in plane strain the incremental properties remain isotropic and are characterized by a single strain-dependent modu...

We determined the local strain profile in sheared lamellar block copolymers. A trilayer model, based on elastic brushes separated by viscous interpenetration zones, captures the rheological response of these materials and provides a measure of the relative contributions of elastic versus viscous strain. The elastic chain distortions were evident from a reversible lamellar contraction, as measur...

ABAQUS offers the possibility to model non-linear isotropic materials as well as linear anisotropic materials. However, it is not possible to use these two capabilities at the same time in order to model anisotropic hyperelastic materials. Gurvich proposed to model such materials by means of the linear superposition of two fictitious materials: a linear anisotropic, and a hyperelastic isotropic...

Some homogeneous elastic materials are capable of sustaining finite equilibrium deformations with discontinuous strains. For materials of this kind, the energetics of isothermal , quasi-static motions may differ from those conventionally associated with elastic behavior. When equilibrium states involving strain jumps occur during such motions, the rate of increase of stored energy in a portion ...

In general, thermodynamic admissibility requires isotropic materials develop reversible deformation induced anisotropy (RDIA) in their elastic stiffnesses. Taking the elastic potential for an isotropic material to be a function of the strain invariants, isotropy of the elastic stiffness is possible under distortional loading if and only if the bulk modulus is independent of the strain deviator ...

Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate stra...

Extremely stretchable self-healing strain sensors based on conductive hydrogels are successfully fabricated. The strain sensor can achieve autonomic self-heal electrically and mechanically under ambient conditions, and can sustain extreme elastic strain (1000%) with high gauge factor of 1.51. Furthermore, the strain sensors have good response, signal stability, and repeatability under various h...

The reinforcement efficiency of carbon nanotubes (CNTs) in epoxy matrix was investigated in the elastic regime. Cyclic uniaxial tensile tests were performed at constant strain amplitude and increasing maximum strain. Post-curing of the epoxy and its composite at a temperature close to the glass transition temperature allowed us to explore the effect of aging on the reinforcement efficiency of C...

Composites made from two linear isotropic elastic materials are considered. It is assumed that only the volume fraction of each elastic material is known. The composite is subjected to a uniform hydrostatic strain. For this case lower bounds on all rth moments of the dilatational strain field inside each phase are obtained for r ≥ 2. A lower bound on the maximum value of the dilatational strain...

New phenomena arise in single-crystal semiconductors when these are fabricated in very thin sheets, with thickness at the nanometer scale. We review recent research on Si and Ge nanomembranes, including the use of elastic strain sharing, layer release, and transfer, that demonstrate new science and enable the fabrication of materials with unique properties. Strain engineering produces new strai...