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Home page > Seminars > Séminaires théorie > Theory Club Monday February 10th at 12:00 in room 734A. Céline Ruscher: "Residual stresses in athermally deformed amorphous solids: insight from atomistic simulations".

Theory Club Monday February 10th at 12:00 in room 734A. Céline Ruscher: "Residual stresses in athermally deformed amorphous solids: insight from atomistic simulations"

Unless otherwise stated, seminars and defences take place at 11:30 in room 454A of Condorcet building.


Residual stresses in athermally deformed amorphous solids: insight from atomistic simulations

Céline Ruscher

Abstract: Amorphous solids are yield-stress materials that flow when a sufficiently large stress is applied. The emergence of plasticity is associated with local rearrangements of particles in shear transfor- mation zones (STs) which interact elastically and can organise spatially in transient or permanent shear-bands. Moreover, individual STs can trigger other unstable regions in the glass thus causing collective failure events in the form of avalanches. In the past 5 years, significant progress has been made to link the scaling properties of avalanches to the underlying microscopic properties. Specifically, the distribution of local residual stresses x was proposed to have the form P (x) ∼ x^θ in the limit of weak residual stresses [1-2], which introduces the exponent θ as a nontrivial scaling exponent that controls the distribution of avalanche sizes. By combining atomistic simulations with the frozen matrix approach [3], we reveal here the evolution of the local residual stress distribution in a 2d binary Lennard-Jones glass upon defor- mation [4]. We find a pseudogap form P(x) ∼ x^θ, in the freshly quenched state and in the early stages of deformation. After a few percent strain, however, P(x) starts to develop a plateau p0 in the small x limit which scales as p0 ∼ L^-p with the system size L in agreement with results from elastoplastic models [5-6]. A direct comparison with the system size scaling of the stress drops shows that the statistical properties of avalanches are controlled by θ in the transient regime and the plateau exponent p in the steady state flow. The emergence of the plateau is related to the discrete nature of mechanical noise and can be explained through a mean-field model which shows p = θ in the thermodynamic limit [4].

[1] J. Lin, A. Saade, E. Lerner, A. Rosso and M. Wyart, EPL, 105, 26003 (2014).

[2] J. Lin, T. Gueudr, A. Rosso and M. Wyart, Phys. Rev. Lett. 115, 168001 (2015).

[3] P. Sollich, CECAM meeting (2011).

[4] C. Ruscher and J.Rottler, arXiv:1908.01081, (2019)

[5] E. E. Ferrero and E. A. Jagla, Soft Matter 15, 9041 (2019).

[6] B. Tyukodi, D. Vandembroucq and C. E. Maloney, Phys. Rev. E 100, 043003 (2019).

Monday February 10th at 12:00 in room 734A


Contact : Équipe séminaires / Seminar team - Published on / Publié le 5 February


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