This article deals with a viscoplastic material model of overstress type. The model is based on a multiplicative decomposition of the deformation gradient into elastic and inelastic part. An additional multiplicative decomposition of inelastic part is used to describe a nonlinear kinematic hardening of Armstrong-Frederick type. Two implicit time-stepping methods are adopted for numerical integr...

Elastomers and gels can often deformmultiple times their original length. The stretchability is insensitive to small cuts in the samples, but reduces markedly when the cuts are large. We show that this transition occurs when the depth of cut exceeds a material-specific length, defined by the ratio of the fracture energy measured in the large-cut limit and the work to rupture measured in the sma...

We study the interaction of highly nonlinear solitary waves propagating in granular crystals with an adjacent linear elastic medium. We investigate the effects of interface dynamics on the reflection of incident waves and on the formation of primary and secondary reflected waves. Experimental tests are performed to correlate the linear medium geometry, materials, and mass with the formation and...

The combination of classical time reversal techniques and nonlinear elastic wave response, induced by the presence of a localized area of damage, brings about a significant enhancement of nonlinear imaging. In this paper, this concept is discussed from a numerical point of view, using multiscale Finite Difference Time Domain and PseudoSpectral Time Domain elastic wave solvers.

The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by u...

We investigate the stability and geometrically nonlinear dynamics of slender rods made of a linear isotropic poroelastic material. Dimensional reduction leads to the evolution equation for the shape of the poroelastica where, in addition to the usual terms for the bending of an elastic rod, we find a term that arises from fluid–solid interaction. Using the poroelastica equation as a starting po...

A robust procedure to estimate nonlinear mechanical properties of thermally sprayed (TS) ceramic coatings is introduced. Such a method is valuable particularly for TS coatings since each may possess unique properties depending upon its processing condition. Traditionally, their responses have been assumed as linear elastic (isotropic or anisotropic) except in very high temperature environments ...

Soft materials have the advantage that their subsurface structure may be imaged utilizing imaging modalities such as ultrasound, magnetic resonance imaging, computed tomography (CT) scans, and optical coherence tomography. In recent decades subsurface displacement fi elds were successfully measured using these imaging modalities. These displacement fi elds are of time-harmonic, transient, or qu...

in many cases, a torsional shaft may be a thick-walled radially inhomogeneous cylindrical object. the hollow shafts made of functionally graded materials (fgms) are such kind of compositions which were studied in this paper. cylindrical fg shafts are composed of ceramic and metallic parts with power function distribution across the radial direction. the ceramic phase is isotropic elastic and th...

In this talk we will show how the mechanical response of an elastic film is affected by subtle geometric properties of its mid-surface. The crucial role here is played by spaces of weakly regular (Sobolev) isometries or infinitesimal isometries. These are the deformations of the mid-surface preserving its metric up to a certain prescribed order of magnitude, and hence contributing to the stretc...