Fig. 3: Intermittent bursts associated with plastic yielding.
τp = 104, f = 1.0 (marked by green triangle in Fig. 1). We monitor the time series of a mean kinetic energy E(t), b potential energy U(t) and c local shear stress Σxy(t), at a value of f < f *(τp) where the burst events are isolated and rare. Note that in the kinetic energy time series, we have subtracted out the centre-of-mass contribution. d–g The displacement field profiles surrounding a single kinetic energy burst event (encircled in a): d show the radial component of the displacement field with a clear shear axis and quadrupolar symmetry (schematically highlighted using thick arrows), and e shows the azimuthal component with signs of vorticity; the arrows in the plots have been scaled up for visibility. f The fourfold symmetry shows up as a dominant l = 4 mode in the power spectrum of the radial component of the displacement field \(u(r,\theta )={\sum }_{l}{u}_{l}(r)\exp (-il\theta )\), where we average over r for better signal to noise. g Spatial profile of the radial component of the displacement shows a 1/r fall from the event. This implies that the deformation associated with a single, isolated yield event is an Eshelby deformation.
