Anisotropic Viscosities of an Oriented Fiber Composite with a Power-Law Matrix

Abstract

Models for the prediction of the longitudinal and transverse elongational viscosities and the inplane and transverse shearing viscosities have been developed for an oriented assembly of discontinuous fibers suspended in both a Newtonian fluid and a power-law fluid with finite yield stress. The present theory is shown to be increasingly ac curate as the fiber volume fraction is increased in contrast to the work of suspension rheology which is largely relegated to dilute and semiconcentrated systems. The approach taken is to assume the fiber kinematics, calculate the resulting fluid motion and determine directly the effective properties of the composite. Solutions are shown to compare favor ably with the results of Batchelor [2] and Christensen [6].