2026-09-21T02:50:04Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/50407 2023-07-11 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Ostoja-Starzewski, Martin Dahmen, Karin A. Zhang, Dansong 2014-09-16T17:12:40Z 2014-09-16T17:12:40Z 2016-09-22T20:59:21Z 2014-08 2014-09-16 2014-08 Many experiments have found that amorphous materials deform via slip avalanches in the plastic regime, which are bursts of plastic flows and show scale free features, as evidenced by a power-law probability distribution of the magnitude of serrations in stress-strain curves. Mesoscale models of amorphous plasticity, depending on assumptions of the interaction between slipped sites, give different predictions of scaling exponents. Atomistic simulation, which does not rely on such assumptions, offers an important approach to a profound understanding of this phenomenon. In this study, we simulate the quasi-static simple shear deformation of 2D amorphous samples with an atomistic approach. Tracking the evolution of stress and potential energy with strain, we find that each avalanche event is marked by a sudden drop in shear stress and potential energy. The relationship between stress drop and energy drop becomes asymptotically linear for increasing avalanche sizes. The probability distributions of stress drops follow a power law, with an exponent of 1.16 ± 0.05. Scaling of the distributions for different system sizes reveals that the maximum avalanche size and the number of events of a given avalanche size scale subextensively with system size, consistent with previous studies. Moreover, the spatial extent of avalanches is measured. It is found that the occurrence of each avalanche is marked by a sudden localization of deformation. Large avalanche events are generally more delocalized than small events, as slips are triggered in broader regions. However, the plastic deformation is still subextensive, not extensive, even for the largest avalanches. Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2014-07-21T12:49:38Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 5 Zhang_Dansong.pdf: 10373098 bytes, checksum: a768c0770552caae5241b4ae0890a533 (MD5) Zhang_Dansong.pdf: 10376270 bytes, checksum: 8684e4ccfd77fde5251145dfeac022d4 (MD5) Zhang_Dansong.pdf: 10376270 bytes, checksum: 8684e4ccfd77fde5251145dfeac022d4 (MD5) Zhang_Dansong.pdf: 10376270 bytes, checksum: 8684e4ccfd77fde5251145dfeac022d4 (MD5) Zhang_Dansong.pdf: 10373098 bytes, checksum: a768c0770552caae5241b4ae0890a533 (MD5) Made available in DSpace on 2014-09-16T17:12:40Z (GMT). No. of bitstreams: 2 Dansong_Zhang.pdf: 10376983 bytes, checksum: 8d1fafc603c4b436cd8480c025d30ce4 (MD5) license.txt: 4063 bytes, checksum: 264f43eea01e642a9a9b8cbbb57482e1 (MD5) Embargo set by: Seth Robbins for item 50518 Lift date: 2016-09-16T17:13:01Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 50518 on 2016-09-22T20:59:21Z. http://hdl.handle.net/2142/50407 en Copyright 2014 Dansong Zhang amorphous plasticity slip avalanches atomistic simulation power-law scaling subextensive Statistics of slip avalanches in sheared amorphous materials based on atomistic simulation text Mechanical Sci & Engineering 1917 Mechanical Engineering 0133 University of Illinois at Urbana-Champaign Thesis M.S. MS:Mechanical Engineerng -UIUC 10KS0133MS