Glass Stability Changes the Nature of Yielding under Oscillatory Shear

Alternating Shear Orientation During Cyclic Loading Facilitates Yielding in Amorphous Materials

“…In the athermal limit, using quasistatic oscillatory shear deformation protocol, it was shown that following a number of periods, a disordered system reaches the so-called 'limit cycle' where the trajectory of each atom becomes exactly reversible after one or more cycles, despite that during each subyield cycle large clusters of atoms can undergo cooperative displacements [10,13]. Interestingly, it was recently shown that highly stable glasses, which were produced either using the swap Monte Carlo algorithm [32] or via mechanical annealing [33], can be reversibly deformed over a relatively broad range of strain amplitudes. When the strain amplitude is above a critical value, the yielding transition usually occurs after a number of transient cycles and it is accompanied by the formation of a shear band across the system [17,18,21,24,25,30].…”

Shear band healing in amorphous materials by small-amplitude oscillatory shear deformation

“…Amorphous alloys typically undergo physical aging, when a system slowly evolves towards lower energy states, and generally this process can be accelerated by external cyclic deformation within the elastic range [45]. Thus, the structural relaxation of disordered solids under periodic loading proceeds via collective, irreversible rearrangements of atoms [12,22,23,25], while at sufficiently low energy levels, mechanical annealing becomes inefficient [35]. The two glass samples considered in the present study were prepared either via mechanical annealing at a temperature not far below the glass transition temperature or by computationally slow cooling from the liquid state.…”

“…(3) was originally introduced by Falk and Langer in order to accurately detect the localized shear transformations that involved swift rearrangements of small groups of atoms in driven disordered solids [47]. In the last few years, this method was widely used to study the collective, irreversible dynamics of atoms in binary glasses subjected to time periodic [16,18,20,22,23,29,31,32,35,37] and startup continuous [48][49][50][51][52][53][54] shear deformation, tension-compression cyclic loading [24,33], prolonged elastostatic compression [55,56], creep [57] and thermal cyclic loading [58][59][60][61][62].…”

“…Notably, it was recently demonstrated that different annealing protocols, namely cyclic shear and swap Monte Carlo, result in equivalent thermodynamic states of well annealed glasses [40]. More recently, it was shown that the critical strain amplitude increases in more stable athermal glasses [35,36], whereas the yielding transition can be significantly delayed in mechanically annealed binary glasses at finite temperature [39]. In general, the formation of a shear band during the yielding transition is accelerated in more rapidly annealed glasses periodically loaded at a higher strain amplitude or when the shear orientation is alternated in two or three spatial dimensions [20,23,28,31,37].…”

Elasto-plastic behavior of amorphous materials: a brief review

“…Indeed, it is an object that is built gradually, often from an accumulation of elementary sheard bands, but not necessarily. It can appear for example from isolated events, in a succession of oscillatory forcings under specific temperature and structural conditions [105,106] and its final shape can appear very gradually [107]. Its progressive accumulation share some analogies with damage.…”