Interactions and orientation in concentrated suspensions of rigid rods: Theory and experiment

A theory for the processing-induced fiber orientation and stress in fiber reinforced-polymer composites is presented. Short-fiber-reinforced polymer composites are represented by concentrated suspensions of rigid rods. In concentrated suspensions, fiber-fiber contact is likely and affects the fiber orientation state and suspension rheology. Fiber orientation is given as a function of the strain in the continuum and the probable effects of physical inter-fiber contact. Continuum stress is calculated from the stress in the fluid and fibers, where fiber stress is a result of the local disturbance in the fluid velocity field and of the inter-fiber contact forces. Fiber orientation is described via probability density function whose transport equation has the form of a generalized advection-diffusion equation with a orientation dependent diffusion. This equation is solved using a finite difference scheme and the results are presented versus experiments with suspensions with planar orientation in planar stretching flow. Experiments and simulation agree that increasing concentrations result in increased interaction-based diffusion.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Sandstrom, Chad Richard

Contributors dc:contributor

• Tucker, Charles L., III

• Engineering, Mechanical

Statement dc:rights

• Copyright 1993 Sandstrom, Chad Richard

Language dc:language

eng

Identifier

AAI9329153
(UMI)AAI9329153

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/20445