Particle rearrangement and softening contributions to the nonlinear mechanical response of glasses

Abstract

Amorphous materials such as metallic, polymeric, and colloidal glasses, exhibit complex preparation-dependent mechanical response to applied shear. We perform numerical simulations to investigate the mechanical response of binary Lennard-Jones glasses undergoing athermal, quasistatic pure shear as a function of the cooling rate $R$ used to prepare them. The ensemble-averaged stress versus strain curve $⟨\sigma (\gamma )⟩$ resembles the spatial average in the large size limit, which appears smooth and displays a putative elastic regime at small strains, a yielding-related peak at intermediate strain, and a plastic flow regime at large strains. In contrast, for each glass configuration in the ensemble, the stress-strain curve consists of many short nearly linear segments that are punctuated by particle-rearrangement-induced rapid stress drops. We quantify the shape of the small stress-strain segments, as well as the frequency and size of the stress drops in each glass configuration. We decompose the stress loss into the loss from particle rearrangements and from softening i.e., the reduction of the slopes of the linear segments in $\sigma (\gamma )$), and then compare the two contributions as a function of $R$ and $\gamma$. For the current studies, the rearrangement-induced stress loss is larger than the softening-induced stress loss, however, softening stress losses increase with decreasing cooling rate. We also characterize the structure of the potential energy landscape along the strain direction for glasses prepared with different $R$, and observe a dramatic change of the properties of the landscape near the yielding transition. We then show that the rearrangement-induced energy loss per strain can serve as an order parameter for the yielding transition, which sharpens for slow cooling rates and in the large system-size limit.

arXiv comment17 pages, 19 figures

References in corpus (32)

• Dynamics of Viscoplastic Deformation in Amorphous Solids
• Theoretical perspective on the glass transition and amorphous materials
• Testing Mode-Coupling Theory for a Supercooled Binary Lennard-Jones Mixture I: The van Hove Correlation Function
• Amorphous Systems in Athermal, Quasistatic Shear
• Fractal free energy landscapes in structural glasses
• Irreversible reorganization in a supercooled liquid originates from localised soft modes
• Subextensive Scaling in the Athermal, Quasistatic Limit of Amorphous Matter in Plastic Shear Flow
• Bulk Metallic Glasses Deform via Slip Avalanches
• Statistical Physics of Fracture, Friction and Earthquake
• The yielding transition in amorphous solids under oscillatory shear deformation
• Shear-transformation-zone theory of plastic deformation near the glass transition
• The potential energy landscape of a model glass former: thermodynamics, anharmonicities, and finite size effects
• Statistical Physics of the Yielding Transition in Amorphous Solids
• Onset of Irreversibility and Chaos in Amorphous Solids Under Periodic Shear
• Shear yielding of amorphous glassy solids: Effect of temperature and strain rate
• Avalanches in Strained Amorphous Solids: Does Inertia Destroy Critical Behavior?
• Persistent memory in athermal systems in deformable energy landscapes
• Macroscopic yielding in jammed solids is accompanied by a non-equilibrium first-order transition in particle trajectories
• Locality and Non-locality in Elasto-plastic Responses of Amorphous Solids
• Criticality in the approach to failure in amorphous solids
• Mechanical Yield in Amorphous Solids: a First-Order Phase Transition
• Shear modulus of simulated glass-forming model systems: Effects of boundary condition, temperature and sampling time
• Statistical Physics of Elasto-Plastic Steady States in Amorphous Solids: Finite Temperatures and Strain Rates
• Energy Barrier Scalings in Driven Systems
• Measurements of the Yield Stress in Frictionless Granular Systems
• The effects of cooling rate on particle rearrangement statistics: Rapidly cooled glasses are more ductile and less reversible
• Stochastic Approach to Plasticity and Yield in Amorphous Solids
• The cooling rate dependence of the shear modulus of amorphous solids
• An Athermal Brittle to Ductile Transition in Amorphous Solids
• Elasticity in Amorphous Solids: Nonlinear or Piece-Wise Linear?
• Non-Affine Displacements and the Non-Linear Response of a Strained Amorphous Solid
• Mechanical Properties and Plasticity of a Model Glass Loaded Under Stress Control

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