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

Sandstrom, Chad Richard

Permalink

https://hdl.handle.net/2142/20445 Copy

Description

Title

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

Author(s)

Sandstrom, Chad Richard

Issue Date

1993

Doctoral Committee Chair(s)

Tucker, Charles L., III

Department of Study

Mechanical Science and Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Engineering, Mechanical

Language

eng

Abstract

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.

Type of Resource

text

Permalink

http://hdl.handle.net/2142/20445

Copyright and License Information

Copyright 1993 Sandstrom, Chad Richard

Owning Collections