Predictors of cavitation in glassy polymers under tensile strain: a coarse grained molecular dynamics investigation

Chain level insights into tensile-compressive asymmetry in glassy and semicrystalline polymers

Using molecular dynamics simulations, we provide chain-level insights into the dissimilarities in rearrangements of polymers under uniaxial tensile and compressive deformation in glassy and semicrystalline samples of varying chain lengths. The organization of polymers under tension and compression is distinctively different. The chains align themselves along the tensile axis leading to a net global nematic ordering of their bonds and end-to-end vectors whereas under compression, the polymers arrange themselves in a plane perpendicular to the compressive axis resulting in emergence of an anti-n…

Structural relaxation of porous glasses due to internal stresses and deformation under tensile loading at constant pressure

The time evolution of the pore size distributions and mechanical properties of amorphous solids at constant pressure is studied using molecular dynamics simulations. The porous glasses were initially prepared at constant volume conditions via a rapid thermal quench from the liquid state to the glassy region and allowing for simultaneous phase separation and material solidification. We found that at constant pressure and low temperature, the porous network becomes more compact and the glassy systems relocate to progressively lower levels of the potential energy. Although the elastic modulus and…

Modeling the viscoelastoplastic response of amorphous glassy polymers

Constitutive equations are derived for the viscoelastoplastic response of amorphous glassy polymers at isothermal loading with small strains. A polymer is treated as an ensemble of cooperatively relaxing regions (CRR) which rearrange at random times as they are thermally agitated. Rearrangement of CRRs reflects the viscoelastic response of the bulk medium. At low stresses, CRRs are connected with each other, which implies that the macro-strain in a specimen coincides with micro-strains in individual relaxing regions. When the average stress exceeds some threshold level, links between CRRs brea…

桥接玻璃中颈缩与剪切带介导的拉伸失效

Bridging necking and shear-banding mediated tensile failure in glasses

本文结合实验与原子尺度模拟，研究了玻璃拉伸失效在颈缩与剪切带介导模式间的转变，揭示了剪切与膨胀驱动塑性的相互作用机制，强调了开发结合两者的弹塑性本构模型的必要性。

通过分子动力学模拟和机械拉伸测试洞察玻璃碳的分子与块体力学性能

Insights to Molecular and Bulk Mechanical Properties of Glassy Carbon Through Molecular Dynamics Simulation and Mechanical Tensile Testing

本研究利用分子动力学模拟填补了玻璃碳力学性能在分子层面的研究空白，揭示了其在拉伸和压缩下不同的应力-应变行为，并预测了弹性模量对应变率和温度的依赖性。

玻璃在 cavitation 失效过程中的大伸长超弹性

Large dilatational hyperelasticity of glasses en route to cavitation failure

研究揭示了玻璃在接近失效时，大和小应力三轴度下的弹性塑性变形差异，发现大三轴度下玻璃表现出强超弹性响应，而小三轴度下则伴随微空腔形成，揭示了玻璃失效的拓扑转变过程。