Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Phys Rev Lett. 2014 Jan 17;112(2):028302. doi: 10.1103/PhysRevLett.112.028302. Epub 2014 Jan 15.
At the microscopic level, plastic flow of a jammed, disordered material consists of a series of particle rearrangements that cannot be reversed by subsequent deformation. An infinitesimal deformation of the same material has no rearrangements. Yet between these limits, there may be a self-organized plastic regime with rearrangements, but with no net change upon reversing a deformation. We measure the oscillatory response of a jammed interfacial material, and directly observe rearrangements that couple to bulk stress and dissipate energy, but do not always give rise to global irreversibility.
在微观水平上，被堵塞、无序的材料的塑性流动由一系列无法通过后续变形逆转的颗粒重排组成。相同材料的无穷小变形没有重新排列。然而，在这些极限之间，可能存在一个具有重新排列但在反向变形时没有净变化的自组织塑性状态。我们测量了被堵塞的界面材料的振动响应，并直接观察到与体应力耦合并耗散能量的重排，但它们并不总是导致全局不可逆性。
