CPA: Composite Property Analysis
Simulations
Index (at Interactive Learning Tools subsite)
This program
uses micro-mechanical models to predict the anisotropic thermoelastic
properties for a variety of composite materials. Properties predicted
include Young's moduli (E11,
E22, and E33), shear moduli
(G12, G13, and G23), Poisson's ratios
(n12, n13, and n23),
and coefficients of thermal expansion.
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This work was conducted
in a joint effort between the University of Delaware and Michigan State University
under the aegis of the National Science Foundation project
"Manufacturing Education and Training Program in Composite
Materials for the DoD and Durable Goods Industries" as part
of the DARPA Supplementary Education Awards.
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Background
Various types of composites can be distinguished by the shape
(or aspect ratio) and state of orientation of the reinforcing
fibers induced by processing conditions. The types of composites
treated include
- Continuous-fiber lamina
- Chopped-fiber sheet molding materials
- Extrusions
- Short-fiber bulk molding materials
- Platelet-reinforced materials
Predicted properties can be displayed in tabular or graphical form.
Features
The introductory page describes the program and presents the user with three options:
Tutorial (which provides an explanation of the various aspects of
composite materials), Theoretical Basis (which describes the
theoretical basis and provides references), and Computation.
Selection of the Computation option leads to the input page shown below.
The user may select the units to be used, choose between a two-component
resin/fiber or three-component resin/fiber/filler compound, and elect to
use volume fraction or weight fraction concentration variables. A variety
of common resins, fibers, and fillers can be selected from the pulldown
menus. The appropriate data for these materials is stored in the program
database.
The user may also enter properties for materials not included in the database.
A variety of microstructures associated with various types of composites
are accessed through the pulldown window for select microstructures. The
user enters a value for the aspect ratio and the orientation parameters.
Selection of certain microstructures fixes some of the orientation parameters.
The user may select from various output modes. If the plot options are
selected, the user may choose which of the thermoelastic properties to view.
Help buttons are associated with key data. Selection of the associated
help button will display that portion of the tutorial related to the selection.
Applications
The program yields predictions for the complete set of thermoelastic
properties. This capability is particularly useful, since full
experimental characterization is not always feasible. The most
important application is sensitivity studies investigating the
influence of constituent properties-composition, aspect ratio,
and process-induced fiber orientation-on the thermoelastic properties.
This feature enables the user to select, design, or investigate
the feasibility of using composite materials to meet stiffness-dominated
design constraints. An interesting feature is the ability to
display the directional dependence of the properties for off-axis
loading. The polar plot displayed here shows the shear modulus,
G12, at various off-axis loading
angles for a sheet molding material with partial fiber alignment.
Prof. John W. Gillespie Jr.
phone: 302-831-8702
fax: 302-831-8525
e-mail: gillespie@ccm.udel.edu
Center for Composite Materials
201 Composites Mfg. Science Lab
University of Delaware
Newark, DE 19716-3144
phone: 302-831-8149
fax: 302-831-8525
e-mail: info@ccm.udel.edu
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