Impact-Activated Solidification of Cornstarch and Water Suspensions


Book Description

This thesis approaches impact resistance in dense suspensions from a new perspective. The most well-known example of dense suspensions, a mixture of cornstarch and water, provides enough impact resistance to allow a person to run across its surface. In the past, this phenomenon had been linked to "shear thickening" under a steady shear state attributed to hydrodynamic interactions or granular dilation. However, neither explanation accounted for the stress scales required for a person to run on the surface. Through this research, it was discovered that the impact resistance is due to local compression of the particle matrix. This compression forces the suspension across the jamming transition and precipitates a rapidly growing solid mass. This growing solid, as a result, absorbs the impact energy. This is the first observation of such jamming front, linking nonlinear suspension dynamics in a new way to the jamming phase transition known from dry granular materials.




Granular Matter


Book Description

Powders have been studied extensively because they arise in a wide variety of fields, ranging from soil mechanics to manufacture of pharmaceuticals. Only recently, however, with the deepening understanding of fractals, chaos, 1/f noise, and self-organization, has it been useful to study the mechanical properties of powders from a fundamental physical perspective. This book collects articles by some of the foremost researchers in the field, including chapters on: the role of entropy in the specification of a powder, by S.F. Edwards (Cambridge); discrete mechanics, by P.K. Haff (Duke); computer simulations of granular materials, by G.C. Barker (Norwich); pattern formation and complexity in granular flow, by R.P. Behringer and G.W. Baxter (Duke); avalanches in real sand piles, by A. Mehta (Birmingham); micromechanical models of failure, by M.J. Adams (Unilever) and B.J. Briscoe (Imperial College); mixing and segregation in particle flows, by J. Bridgwater (Birmingham); and hard-sphere colloidal suspensions, by P. Bartlett (Bristol) and W. van Megen (Melbourne).




Granular Physics


Book Description

2007 account of developments in granular physics for researchers in statistical and mathematical physics.




Handbook of Granular Materials


Book Description

Granular systems arise in a variety of geological and industrial settings, from landslides, avalanches, and erosion to agricultural grains and pharmaceutical powders. Understanding the underlying physics that governs their behavior is the key to developing effective handling and transport mechanisms as well as appropriate environmental policies.Han




Granular Media


Book Description

Provides the state-of-the-art of the physics of granular media for graduate students and researchers in physics, applied mathematics and engineering.




Wet Granular Matter


Book Description

1. Introduction. 1.1. The significance of wet granular matter. 1.2. Energy scales. 1.3. Typical questions to be asked. 1.4. How we shall proceed -- 2. Grains and granular fluids. 2.1. Grains. 2.2. Granular fluids. 2.3. Conclusions -- 3. Wetting. 3.1. Planar substrates. 3.2. Rough substrates. 3.3. Conclusions -- 4. Capillary forces. 4.1. Capillary bridge between flat walls. 4.2. Capillary bridge between spherical bodies. 4.3. Capillary bridge between irregular grains. 4.4. Force networks. 4.5. Conclusions -- 5. Wet granular gases. 5.1. Dynamical aspects of capillary bridges. 5.2. Free cooling and clustering. 5.3. Liquid-gas coexistence. 5.4. Collective phenomena far from thermal equilibrium. 5.5. Conclusions -- 6. Wet granular piles. 6.1. Geometrical aspects of granular piles. 6.2. Regimes of wetness. 6.3. Mechanical properties of wet granular piles. 6.4. Phase transitions in wet granular piles. 6.5. Conclusions -- 7. Special topics. 7.1. The physics of sand castles. 7.2. Immiscible granular suspensions. 7.3. Quicksand and quickclay




The Physics of Granular Media


Book Description

Despite extensive empirical experience, there is both a scientific challenge and a technological need to develop an understanding of the mechanisms underlying the flow of grains. This new reference provides quick access to the current level of knowledge, containing review articles covering recent developments in the field of granular media from the viewpoints of applied, experimental, and theoretical physics. In short, a must-have for advanced researchers and specialists as well as a useful starting point for anyone entering this field. The authors represent different directions of research in the field, with their contributions covering: - Static properties - Granular gases - Dense granular flow - Hydrodynamic interactions - Charged and magnetic granular matter - Computational aspects




Physics of Granular Media


Book Description

Sand, flour, smoke, stone, and ceramics, are some of the many granular solids that show up in one form or another in nearly every industry and science. Different approaches to representing structural disorder in such materials, and the effect on its properties, are presented to physicists, materials




Built on Sand


Book Description

Explaining the science contained in a simple assembly of grains—the most abundant form of matter present on Earth. Granular media—composed of vast amounts of grains, consolidated or not—constitute the most abundant form of solid matter on Earth. Granular materials assemble in disordered configurations scientists often liken to a bag of marbles. Made of macroscopic particles rather than molecules, they defy the standard scheme of classification in terms of solid, liquid, and gas. Granular materials provide a model relevant to various domains of research, including engineering, physics, and biology. William Blake famously wished “To See a World in a Grain of Sand”; in this book, pioneering researchers in granular matter explain the science hidden behind simple grains, shedding light on collective behavior in disordered settings in general. The authors begin by describing the single grain with its different origins, shapes, and sizes, then examine grains in piled or stacked form. They explain the packing fraction of granular media, a crucial issue that bears on the properties displayed in practical applications; explore small-scale deformations in piles of disordered grains, with particular attention to friction; and present theories of various modes of disorder. Along the way, they discuss such concepts as force chains, arching effects, wet grains, sticky contacts, and inertial effects. Drawing on recent numerical simulations as well as classical concepts developed in physics and mechanics, the book offers an accessible introduction to a rapidly developing field.