Related Experiment Video
Updated: Sep 25, 2025
06:07
Studying Large Amplitude Oscillatory Shear Response of Soft Materials
Published on: April 25, 2019
13.0K
Cooperative effects driving the multi-periodic dynamics of cyclically sheared amorphous solids
Asaf Szulc1, Muhittin Mungan2, Ido Regev3
1Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
The Journal of Chemical Physics
|April 30, 2022
Summary
Plasticity in amorphous solids arises from soft spots. Interactions between these soft spots cause them to alternate between active and idle states, leading to multi-periodic behavior in the material.
Area of Science:
- Physics
- Materials Science
- Condensed Matter Physics
Background:
- Amorphous solids exhibit plastic behavior under cyclic forcing, sometimes entering multi-periodic states where particles return to initial positions after multiple cycles.
- Plasticity in these materials is attributed to local rearrangements known as soft spots or shear transformation zones.
- Interactions between soft spots, modeled as hysteretic two-state entities, are known to contribute to multi-periodic behavior, but the mechanism remains unclear.
Purpose of the Study:
- To elucidate the mechanism by which interactions between soft spots facilitate multi-periodic behavior in amorphous solids.
- To investigate the role of cooperative effects and frustrated interactions in driving these phenomena.
Main Methods:
- Development and analysis of a model of random interacting two-state systems.
- Utilizing molecular dynamics simulations to observe and analyze system behavior.
- Investigating oscillations in the switching field magnitudes of soft spots.
Main Results:
- Multi-periodicity emerges from oscillations in the switching field magnitudes of soft spots.
- These oscillations cause soft spots to cycle between active and idle states during forcing.
- Frustrated interactions between soft spots drive cooperative effects that lead to these oscillations.
Conclusions:
- The study reveals that cooperative effects from frustrated interactions in soft spots are key to achieving multi-periodicity.
- Understanding these mechanisms offers insights into controlling memory effects in frustrated hysteretic systems.
- This work provides a fundamental understanding of plasticity and memory in amorphous materials.
Related Concept Videos
01:20Elastic Strain Energy for Shearing Stresses
309
As discussed in previous lessons, strain energy in a material is the energy stored when it is elastically deformed, a concept crucial in materials science and mechanical engineering. This energy results from the internal work done against the cohesive forces within the material. When a material undergoes shearing stress and corresponding shearing strain, the strain energy density, which is the energy stored per unit volume, is calculated. Within the elastic limit, where the stress is...
309
01:06Forced Oscillations
6.8K
When an oscillator is forced with a periodic driving force, the motion may seem chaotic. The motions of such oscillators are known as transients. After the transients die out, the oscillator reaches a steady state, where the motion is periodic, and the displacement is determined.
6.8K
01:20Shearing Strain
667
The shearing strain represents a cubic element's angular change when subjected to shearing stress. This type of stress can transform a cube into an oblique parallelepiped without influencing normal strains. The cubic element experiences a significant transformation when exposed solely to shearing stress. Its shape alters from a perfect cube into a rhomboid, clearly demonstrating the effect of shearing strain. The degree of this strain is considered positive if it reduces the angle between...
667
01:19Shearing Stress
922
Shearing stress, denoted by the Greek letter tau (τ), is stress caused by forces acting transversely on an object. These forces create internal ones within the entity in the plane where the external forces are applied. The resultant of these internal forces is the shear in the section.
The average shearing stress can be calculated by dividing the shear by the area of the cross-section.
The average shearing stress can be calculated by dividing the shear by the area of the cross-section.
922
01:23Relation Between the Distributed Load and Shear
800
Understanding the relationship between the distributed load and shear force in structural analysis is crucial for analyzing beams subjected to various loading conditions. Consider the case of a beam experiencing a distributed load, two concentrated loads, and a couple moment.
800
01:15Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity
340
Deformation occurs in axial and transverse directions when an axial load is applied to a slender bar. This deformation impacts the cubic element within the bar, transforming it into either a rectangular parallelepiped or a rhombus, contingent on its orientation. This transformation process induces shearing strain. Axial loading elicits both shearing and normal strains. Applying an axial load instigates equal normal and shearing stresses on elements oriented at a 45° angle to the load axis.
340