Effect of the Ratio lK/p on Glassy-Polymeric Shear Deformation Mechanisms
Effect of the Ratio lK/p on Glassy-Polymeric Shear Deformation Mechanisms
复制标题
lK/p 比率对玻璃态聚合物剪切变形机制的影响
DOI：
10.1021/acs.macromol.8b00651
复制
发表时间：
2018
期刊：
影响因子：
5.5
通讯作者：
R. Hoy
中科院分区：
文献类型：
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作者：
Hong T. T. Nguyen;R. Hoy
通过分子动力学模拟，我们研究了链刚度如何影响玻璃态聚合物在施加剪切下的变形。由柔性链组成的松散缠结系统表现出强剪切带和随后的应变软化，而由半柔性链组成的紧密缠结系统则没有表现出这些。对于所有系统，应力-应变曲线中的拐点对应于断链的开始，但非线性应变硬化持续到更大的应变。紧密缠结的系统在通过断链断裂之前会积累相当大的弹性能。这导致它们的塑性流动更加不均匀，并且它们最终会沿着比松散缠结的对应物更尖锐的断裂面失效，而松散缠结的对应物会通过链拉拔失效。我们使用现代可塑性指标来量化这些差异，并将它们与链刚度相关的分段包装效率和链间相互渗透的差异联系起来。看来额外的...
Using molecular dynamics simulations, we study how chain stiffness affects how glassy polymers deform under applied shear. Loosely entangled systems composed of flexible chains exhibit strong shear banding and subsequent strain softening whereas tightly entangled systems composed of semiflexible chains exhibit neither of these. For all systems, inflection points in stress–strain curves correspond to the onset of chain scission, but nonlinear strain hardening continues up to much larger strains. Tightly entangled systems build up considerable elastic energy before fracturing via chain scission. This causes their plastic flow to be far more heterogeneous, and they ultimately fail along significantly sharper fracture planes than their loosely entangled counterparts, which fail via chain pullout. We quantify these differences using modern plasticity metrics and relate them to chain-stiffness-dependent differences in segmental packing efficiency and interchain interpenetration. It appears that the additional s...
DOI：
10.1126/science.aai8830
发表时间：
2017-11-24
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Cubuk ED;Ivancic RJS;Schoenholz SS;Strickland DJ;Basu A;Davidson ZS;Fontaine J;Hor JL;Huang YR;Jiang Y;Keim NC;Koshigan KD;Lefever JA;Liu T;Ma XG;Magagnosc DJ;Morrow E;Ortiz CP;Rieser JM;Shavit A;Still T;Xu Y;Zhang Y;Nordstrom KN;Arratia PE;Carpick RW;Durian DJ;Fakhraai Z;Jerolmack DJ;Lee D;Li J;Riggleman R;Turner KT;Yodh AG;Gianola DS;Liu AJ
通讯作者：
Liu AJ