Universal structural characteristics of planar granular packs
Takashi Matsushima1, Raphael Blumenfeld2
1Department of Engineering Mechanics and Energy, University of Tsukuba, Tsukuba 305-8573, Japan.
Physical Review Letters
|March 25, 2014
Summary
Structural self-organization in granular materials is predictable. For same-variance disc size distributions, key structural properties are independent of initial conditions, suggesting packing protocols primarily determine granular structures.
Area of Science:
- Physics of granular materials
- Computational materials science
- Statistical mechanics
Background:
- Understanding granular material self-organization is crucial for predictive modeling.
- Preparation methods and grain characteristics influence material structure.
- Current models often struggle with the complexity of polydisperse granular systems.
Purpose of the Study:
- To investigate the influence of preparation protocols on the structure of granular materials.
- To determine if structural properties of equilibrated granular packs are universal.
- To identify key factors governing the self-organization of polydisperse granular systems.
Main Methods:
- Numerical simulation of 60 mechanically equilibrated polydisperse disc packs.
- Generation of packs using two distinct preparation protocols.
- Analysis of coordination number, packing fraction, quadron volume, and cell order distributions.
Main Results:
- Mean coordination number is independent of initial conditions, friction, and disc size distribution (DSD) for same-variance DSDs.
- Quadron volume and cell order distributions exhibit universal forms, independent of preparation and DSD.
- Identified apparent universality in structural properties of equilibrated granular packs.
Conclusions:
- Equilibrated granular structures may be primarily determined by the packing protocol and higher moments of the DSD.
- Findings challenge conventional wisdom regarding the dominant factors in granular self-organization.
- Suggests a pathway towards more predictive models for granular materials.
Related Concept Videos
02:22Structures of Solids
17.8K
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
17.8K
01:25Shape and Texture of Coarse Aggregate
1.3K
Aggregate shape is classified based on the relative sharpness or roundness of the edges and corners. This classification includes categories like rounded, angular, elongated, and flaky, each with specific characteristics. Rounded aggregates, fully shaped by attrition, are typical of river or seashore gravel, while angular aggregates, such as crushed rock, have well-defined edges. Aggregates that are elongated and flaky are less desirable, as they can reduce the workability and strength of...
1.3K
02:42Ionic Crystal Structures
18.0K
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
18.0K
02:37Metallic Solids
16.4K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and...
16.4K
01:22Planar Rigid-Body Motion
1.4K
Understanding the movement of a rigid body in planar motion involves recognizing that every particle within this body is traversing a path that maintains a consistent distance from a specific plane. This concept is fundamental in the study of physics and mechanical engineering, and it allows us to comprehend better how objects move in space.
Planar motion is typically divided into three distinct categories. The first is rectilinear translation, demonstrated by a subway train that moves along...
Planar motion is typically divided into three distinct categories. The first is rectilinear translation, demonstrated by a subway train that moves along...
1.4K
01:30Classification of Leukocytes
9.0K
Leukocytes are classified into two groups based on the presence or absence of cytoplasmic granules. Granular leukocytes, which contain granules, belong to the myeloid lineage and are divided into three subtypes: neutrophils, eosinophils, and basophils. These cells are roughly spherical and characterized by the granules in their cytoplasm.
Neutrophils are the most abundant type of granular leukocytes, comprising 50-70% of all leukocytes. They feature small, evenly distributed granules and a...
Neutrophils are the most abundant type of granular leukocytes, comprising 50-70% of all leukocytes. They feature small, evenly distributed granules and a...
9.0K