Analysis of Low-Frequency Vibrational Modes and Particle Rearrangements in Marginally Jammed Amorphous Solid under Quasi-Static Shear

• Published in: Chinese physics letters Vol. 32; no. 12; pp. 101 - 104
• Main Author: 董远湘 张国华 孙其诚 赵雪丹 牛晓娜
• Format: Journal Article
• Language: English
• Published: 01.12.2015
• Subjects: 低频率; 应力-应变曲线; 振动模式; 粒子; 重排; 静态剪切; 非晶固体; 颗粒系统
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/32/12/126201

We present the numerical simulation results of a model granular assembly formed by spherical particles with tIertzian interaction subjected to a simple shear in the athermal quasi-static limit. The stress-strain curve is shown to separate into smooth, elastic branches followed by a subsequent plastic event. Mode analysis shows that the lowest-frequency vibrational mode is more localized, and eigenvalues and participation ratios of low- frequency modes exhibit similar power-law behavior as the system approaches plastic instability, indicating that the nature of plastic events in the granular system is also a saddle node bifurcation. The analysis of projection and spatial structure shows that over 75% contributions to the non-affine displacement field at a plastic instability come from the lowest-frequency mode, and the lowest-frequency mode is strongly spatially correlated with local plastic rearrangements, inferring that the lowest-frequency mode could be used as a predictor for future plastic rearrangements in the disordered system jammed marginally.