Related Experiment Video
Updated: Jul 15, 2026
12:30
High-pressure, High-temperature Deformation Experiment Using the New Generation Griggs-type Apparatus
Published on: April 3, 2018
Athermal shear-transformation-zone theory of amorphous plastic deformation. I. Basic principles
Eran Bouchbinder1, J S Langer, Itamar Procaccia
1Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel.
Summary
We present an athermal shear-transformation-zone (STZ) theory for amorphous plasticity. This simplified model offers broader applicability and clearer interpretation of material yielding without thermal fluctuations.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Rheology
Background:
- Amorphous plasticity is governed by irreversible molecular rearrangements.
- Existing theories often rely on thermal activation, complicating thermodynamic consistency.
- Shear-transformation-zone (STZ) theory models these rearrangements.
Purpose of the Study:
- To develop a simplified, athermal version of STZ theory for amorphous plasticity.
- To provide a clearer interpretation of yielding phenomena.
- To establish a framework applicable where thermal effects are negligible.
Main Methods:
- Formulation of an athermal shear-transformation-zone (STZ) theory.
- Incorporation of an explicit distribution of STZ transition thresholds.
- Analysis of yielding as a transition between jammed and flowing states.
Main Results:
- The athermal STZ theory demonstrates broader applicability and simplicity compared to thermal models.
- Thermodynamic consistency is achieved without special considerations.
- Yielding is interpreted as a clear exchange of dynamic stability between states.
Conclusions:
- The developed athermal STZ theory provides a robust framework for understanding amorphous plasticity.
- The theory simplifies analysis and enhances clarity in interpreting material behavior.
- An effective temperature concept remains crucial for relating STZ density to system disorder.
Related Concept Videos
01:19Plastic Deformations
Plastic deformation represents a fundamental concept in materials science, which explains the irreversible change in the shape of a material when it experiences stress beyond its elastic capability. This phenomenon is important in structural engineering, especially in designing and analyzing cantilever beams—structures that are securely fixed at one end and bear loads at the opposite end. When these beams are subjected to loads within their elastic range, they will return to their original...
01:14Plastic Deformations
It is essential to understand how structural members behave under plastic deformation when the bending stress exceeds the material's yield strength. This state of deformation permanently alters the shape of the member, in contrast to the linear elastic behavior observed before yielding. The strain at any point in the member is expressed in terms of maximum strain. Notably, the neutral axis, which coincides with the centroid during elastic bending, shifts away from the centroid under plastic...
01:20Plastic Deformation in Circular Shafts
When materials are subjected to forces that surpass their yield strength, they undergo a process known as plastic deformation. This results in a permanent alteration or strain in their structure. This concept can be specifically applied to circular shafts, where the deformation leads to a change in its shape. The precise evaluation of this plastic deformation requires understanding the stress distribution within the circular shaft, which is achieved by calculating the maximum shearing stress in...
01:19Thermal Strain
Thermal strain is a concept that arises when we consider how temperature changes affect structures. Unlike the conventional assumption that structures remain constant under load, real-world scenarios often involve temperature fluctuations that can significantly impact these structures. Consider a homogeneous rod with a uniform cross-section resting freely on a flat horizontal surface. If the rod's temperature increases, the rod elongates. This elongation is proportional to the temperature...
01:12Transformation of Plane Strain
When analyzing elongated structures like bars subjected to uniformly distributed loads, it is essential to understand the transformation of plane strain when coordinate axes are rotated. This transformation helps to assess how material deformation characteristics vary with orientation, which is crucial in materials science and structural engineering.
Under plane strain conditions, typical for members where one dimension significantly exceeds the others, deformations and resultant strains are...
Under plane strain conditions, typical for members where one dimension significantly exceeds the others, deformations and resultant strains are...
01:21Plastic Behavior
A material's elastic behavior is characterized by the disappearance of stress once the load is removed, allowing the material to return to its original state. However, when stress surpasses the yield point, yielding commences, marking the onset of plastic deformation or permanent set. This change from elastic to plastic behavior is influenced by the peak stress value and the duration before the load is removed. An intriguing observation occurs when a specimen is loaded, unloaded, and reloaded.