English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Mechanical deformation of nanopillars displays features that are distinctlydifferent from the bulk behavior of single crystals: Yield strength increaseswith decreasing size and plastic deformation comes together with strain burstsor/and stress drops (depending on loading conditions) with a very strongsensitivity of the stochasticity character on material preparation andconditions. The character of the phenomenon is standing as a paradox: Whilethese bursts resemble the universal, widely independent of material conditions,noise heard in bulk crystals using acoustic emission (AE) techniques, theystrongly emerge primarily with decreasing size and increasing strength innanopillars. In this paper, we present a realistic but minimal discretedislocation plasticity model for the elasto-plastic deformation of nanopillarsthat is consistent with the main experimental observations of nano pillarcompression experiments and provides a clear insight to this paradox. Withincreasing sample size, the model naturally transitions between the typicalprogressive behavior of nanopillars to a behavior that resembles evidence forbulk mesoscale plasticity. The combination of consistent strengthening, largeflow stress fluctuations and critical avalanches is only observed in the {\itdepinning regime} where obstacles are much stronger than dislocation sources;in contrast, when dislocation source strength becomes comparable to obstaclebarriers, then yield strength size effects are absent but plasticity avalanchedynamics is strongly universal, across sample width and aspect-ratio scales.Finally, we elucidate the mechanism that leads to the connection betweendepinning and size effects in our model dislocation dynamics. In this way, ourmodel builds a way towards unifying statistical aspects of mechanicaldeformation across scales.

Obstacles and sources in dislocation dynamics: Strengthening and statistics of abrupt plastic events in nanopillar compression