Otsuki Michio, Hayakawa Hisao
Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
Yukawa Institute for Theoretical Physics, Kyoto University, Kitashirakawaoiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan.
Phys Rev E. 2020 Mar;101(3-1):032905. doi: 10.1103/PhysRevE.101.032905.
We numerically study the linear response of two-dimensional frictional granular materials under oscillatory shear. The storage modulus G^{'} and the loss modulus G^{''} in the zero strain rate limit depend on the initial strain amplitude of the oscillatory shear before measurement. The shear jammed state (satisfying G^{'}>0) can be observed at an amplitude greater than a critical initial strain amplitude. The fragile state is defined by the emergence of liquid-like and solid-like states depending on the form of the initial shear. In this state, the observed G^{'} after the reduction of the strain amplitude depends on the phase of the external shear strain. The loss modulus G^{''} exhibits a discontinuous jump corresponding to discontinuous shear thickening in the fragile state.
我们对二维摩擦颗粒材料在振荡剪切下的线性响应进行了数值研究。零应变率极限下的储能模量(G^{'})和损耗模量(G^{''})取决于测量前振荡剪切的初始应变幅度。在大于临界初始应变幅度的振幅下，可以观察到剪切堵塞状态（满足(G^{'}>0)）。脆弱状态是由取决于初始剪切形式的类液态和类固态的出现来定义的。在这种状态下，应变幅度减小后观察到的(G^{'})取决于外部剪切应变的相位。损耗模量(G^{''})表现出与脆弱状态下的不连续剪切增稠相对应的不连续跳跃。
