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| Because composite materials can exhibit material anisotropy with different properties in different directions, the thermoelastic properties of the composite are indexed to indicate the direction. The indices used in this program are shown in the Figure below. | ||||||
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| The microstructural descriptors required for the prediction of properties are the aspect ratio (or effective aspect ratio), a, of the reinforcing agent and factors "f" describing the state of orientation of the reinforcing agent. The orientation factors have been scaled so that a value of "1" corresponds to perfect alignment and a value of "0" represents a random array of fibers. Values between "0" and "1" indicate intermediate states of partial orientation. As shown in the Figure below, these microstructural features can be used to distinguish between a wide class of composite materials |
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| The user may select from a variety of polymer matrix materials and isotropic fibers. The thermoelastic properties for these default materials are accessed from a stored database. Alternately, the user may specify thermoelastic properties for isotropic materials of their choice. The concentration must be specified either as volume fraction or weight fraction. The aspect ratio must be specified with 0<a<1 corresponding to platelets, a=1 representing spherical particles, and a>1 describing fibers. Fibers with aspect ratios greater than 100 behave as continuous fibers. For some microstructures, the user can specify various states of orientation. The program can also be used to predict properties for three component systems of resin/fiber/filler in which the filler aspect ratio is taken as unity. The output can be selected to be in tabular or graphic form. Provisions are available to obtain plots as a function of volume fraction, aspect ratio, or orientation factor over specified ranges. This feature is particular useful for sensitivity analyses of the influence of processing induced changes in the microstructure on the behavior of the composite. |
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CONTENT AND ORGANIZATION COMPUTATIONAL ALGORITHMS PROGRAMMING GRAPHICS & DESIGN CONTACT Center for Composite Materials yarlagan@ccm.udel.edu |
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