Poiseuille flow of soft glasses in narrow channels: From quiescence to steady state

Chaudhuri, Pinaki; Horbach, Jürgen

doi:10.1103/physreve.90.040301

Cited by 13 publications

(13 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This behavior bears similarities with the transition from the solid-to-fluidized branch that we observe (see Fig. 3), with an important difference: The study by Chaudhuri & Horbach [73] does not report the existence of metastable states; i.e., once the fluidized state is reached it is shown to persist for the whole simulation time. However, the time spent by the system in the solid phase is remarkably long, much longer than the time that would be observed for an unstable state.…”

Section: Discussionsupporting

confidence: 80%

“…In the specific case of the theoretical model by Picard et al [29] this may be possibly related to the minimalistic nature of the model; i.e., no noise is added [18]. In order to stress the combined role of multiple rheological branches and space correlations, it is worthwhile to further connect our observations with some other results presented in the literature [53,73]. A recent work by Chaudhuri et al [53] studied the interplay between the system size and the cooperative length in the flow arrest.…”

Section: Discussionmentioning

confidence: 62%

“…This contrasts with our observations. The interplay between system size and cooperative scale was also highlighted in another work by Chaudhuri & Horbach [73], studying the transition to the flowing regime in a pressure-driven flow for a Yukawa binary fluid [75,76]. When the cooperative length is of the order of the system size, it is shown that (in the long time limit) the system fluidizes nearly homogeneously.…”

Section: Discussionmentioning

confidence: 74%

“…In other words, one may argue that in Ref. [73] two metastable branches coexist although the possibility of transition between the branches has not been inves-…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Metastability at the Yield-Stress Transition in Soft Glasses

2018

View full text Add to dashboard Cite

We study the solid-to-liquid transition in a two-dimensional fully periodic soft-glassy model with an imposed spatially heterogeneous stress. The model we consider consists of droplets of a dispersed phase jammed together in a continuous phase. When the peak value of the stress gets close to the yield stress of the material, we find that the whole system intermittently tunnels to a metastable "fluidized" state which relaxes back to a metastable "solid" state by means of an elastic-wave dissipation. This macroscopic scenario is studied through the microscopic displacement field of the droplets, whose time-statistics displays a remarkable bimodality. Metastability is rooted in the existence, in a given stress range, of two distinct stable rheological branches as well as long-range correlations (e.g., large dynamic heterogeneity) developed in the system. Finally, we show that a similar behavior holds for a pressure-driven flow, thus suggesting possible experimental tests.

show abstract

Section: Discussionsupporting

confidence: 80%

Section: Discussionmentioning

confidence: 62%

Section: Discussionmentioning

confidence: 74%

“…In other words, one may argue that in Ref. [73] two metastable branches coexist although the possibility of transition between the branches has not been inves-…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Metastability at the Yield-Stress Transition in Soft Glasses

2018

View full text Add to dashboard Cite

show abstract

“…Furthermore, the residual stresses are found to be heterogeneously distributed in the glass sample, thus reflecting the memory of the shear band, as formed in the sheared system. We analyze the formation of shear bands by a methodology that we have recently developed in the context of a sheared soft-sphere mixture in its glass state [13,14]. To this end, maps of the local meansquared displacement (MSD) are computed.…”

mentioning

confidence: 99%

Shear band relaxation in a deformed bulk metallic glass

et al. 2016

View full text Add to dashboard Cite

Relaxation of shear bands in a Pd 40 Ni 40 P 20 bulk metallic glass was investigated by a combination of radiotracer diffusion and molecular dynamics (MD) simulations, allowing to determine for the first time the effective activation enthalpy of diffusion along shear bands in a deformed glass. The shear bands relax during annealing below the glass transition temperature and the diffusion enhancement reveals unexpectedly a nonmonotonous behavior. The development of shear bands and the subsequent relaxation of stresses after switching off the shearing are characterized on microscopic to mesoscopic length scales by MD simulation subjecting the model glass to a constant strain rate. Mean-squared displacements as well as strain maps indicate that the heterogeneity, as manifested by shear bands in the systems under shear, persist after the shear is switched off. We observe a further relaxation of residual stresses that remain localized in regions where the shear band has been present before, although the system is -different from the macroscopic experiment -homogeneous with respect to the local density. These results indicate that even on a local scale one may expect strong dynamic heterogeneity in deformed glassy solids due to shear banding. The results thus suggest that plastically deformed metallic glasses present poly-amorphous systems that necessitate descriptions that are analogous to multiphase materials including the presence of heterophase interfaces.Although non-homogenous plastic deformation of bulk metallic glasses (BMGs) via the formation of shear bands attracted increased attention in the past [1,2], it is still far from being resolved, see e.g. the reviews in [3,4]. As a generally accepted concept, so-called "shear transformation zones" (STZ), i.e. areas in which groups of atoms collectively undergo a local shear transformation, have been introduced [5] as "unit carriers" of plastic deformation in metallic glasses. A cross-over from random 3-dimensional shear events (STZ formation) to correlated 2-dimensional dynamics has been brought forward to explain the observed shear banding in metallic glasses [6]. Although the activation of a single STZ event is not inevitably related to a change of the excess volume, shear bands are often described in terms of excess volume accumulation [3,7]. Recently, we investigated diffusion in deformed Pd 40 Ni 40 P 20 (at. %; in what follows we will use the abbreviation PdNiP) glass, in which almost a single family of shear bands was introduced, and were able to unambiguously prescribe the observed enormous enhancement of the diffusion rate to an ultra-fast atomic transport along these quasi-2-dimensional pathways [8]. The tracer concentrations in the corresponding concentration profiles, which were related to shear band diffusion, were shown to scale with the number density of the introduced shear bands (that in turn scales with the imposed strain),

show abstract

Two-dimensional magnetic colloids under shear

2016

View full text Add to dashboard Cite

Complex rheological properties of soft disordered solids, such as colloidal gels or glasses, inspire a range of novel applications. However, the microscopic mechanisms of their response to mechanical loading are not well understood. Here, we elucidate some aspects of these mechanisms by studying a versatile model system, i.e. two-dimensional superparamagnetic colloids in a precessing magnetic field, whose structure can be tuned from a hexagonal crystal to a disordered gel network by varying the external field opening angle θ. We perform Langevin dynamics simulations subjecting these structures to a constant shear rate and observe three qualitatively different types of material response. In hexagonal crystals (θ = 0°), at a sufficiently low shear rate, plastic flow occurs via successive stress drops at which the stress releases due to the formation of dislocation defects. The gel network at θ = 48°, on the contrary, via bond rearrangement and transient shear banding evolves into a homogeneously stretched network at large strains. The latter structure remains metastable after switching off of the shear. At θ = 50°, the external shear makes the system unstable against phase separation and causes a failure of the network structure leading to the formation of hexagonal close packed clusters interconnected by particle chains. At a microcopic level, our simulations provide insight into some of the mechanisms by which strain localization as well as material failure occur in a simple gel-like network. Furthermore, we demonstrate that new stretched network structures can be generated by the application of shear.

show abstract

Poiseuille flow of soft glasses in narrow channels: From quiescence to steady state

Cited by 13 publications

References 41 publications

Metastability at the Yield-Stress Transition in Soft Glasses

Metastability at the Yield-Stress Transition in Soft Glasses

Shear band relaxation in a deformed bulk metallic glass

Two-dimensional magnetic colloids under shear

Contact Info

Product

Resources

About