Pedro Romero, Shanfu Zheng and Alberto M' Cuitio

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Discovering Material Behavior from the Bottom-up

• Pedro Romero, Shanfu Zheng and Alberto M. Cuitiño

Semi-Annual Review Materials Science Cluster
Center for Advanced Food Technology Rutgers
University November 6, 2002
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Motivation

• The motivation for the present project is to
  developed the necessary computational tools to
  aid in the design and manufacture of products
  with desired textural characteristics. The
  methodology is based on the current
  state-of-the-art methods of materials science and
  computational mechanics, which incorporate a
  hierarchical set of models describing the physics
  of the processes at different scales or a
  multiscale modeling approach.
• The goal is to develop a general methodology
  capable of simulating many potential scenarios
  with assess the advantages and drawbacks of a a
  particular design.

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Overall Goal
From the bottom of the material components as
molecular, crystal grains to discover the
material behaviors as well as the effect of
Material Design
Mesoscopic Models To describe the cell shape,
size, deformation mechanism, collapse, fracture,
strain-rate dependency etc.
Structural Design
Parameters to be designed Density and size
distribution of cells
Length scale
mm
m
nm ?m
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Structural Design
Bubble Model Each cell is a bubble with uniform
shell thickness and deforms from a spherical
shape to an ellipsoidal one during the crushing
of cellular materials.
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Structural Design
Microstructure of Yellow Cake
The cell size is distributed from 0.02mm 2.5
mm. Bubble model should be able to take account
of the effect of size distribution.
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Structural Design
Superposition
P P1 ? P2
Yellow cake
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Structural Design
Effect of density
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Structural Design
Effect of size distribution of cells
Skewness S
Variance ?
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Material Design

• Need
• Mechanical properties of solid material as E, ?,
  ?y, etc
• Effect of additives and manufacture processes
• Deformation behaviors of representative cell
• Less empirical

• How to get
• Experiments
• Deeper analysis of materials

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Material Design
Metallic foams
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Material Design

• Microstructure ? Meso-structure

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Material Design
Deformation of a cell member
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Applications

• The potential application of the present
  development is purposely open to simulate a wide
  array of material systems exhibiting a cellular
  structure. Different mechanics are incorporated
  to account for very different potential
  scenarios. From brittle systems such as cereal to
  plastic ones such as sponge cake. Especial
  emphasis is placed on the model development in
  order to characterize the material response by
  parameters with clear physical meaning, which are
  therefore obtainable from experiment or
  fine-scale simulations.
• The value for potential users is based on the
  ability of providing predictive capabilities. Our
  approach is then to move from engineering models
  or quasi-empirical model to engineering science
  models, which allow for controlled approximations
  and physical assumptions

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Material Design