ABSTRACT
The main predictions of the Dinh-Armstrong theory were verified by Bibbo et a!. [30]. Shown in Fig. 11.4 are zero-strain data on nylon as well as copper fibers suspended in Newtonian media. The solid lines represent the theory: curves marked aligned and random arc obtained for the appropriate spacing between particles. Vertical dashed lines denote the limits of validity of the theory. Data for the longer fibers were corrected for wall effects. and the extent ol' correction is shown by lhc two solid points lhat are uncorrected data. As expected. the fiber contribution to the suspension viscosity is proportional to nL 3• Figure 11.5 shows how the viscosity of 2-mm-long nylon fibers suspended in silicone oil changes with the total strain. Clearly. the data depend uniquely on strain and exhibit a slight maximum. However. there is a mismatch between theory and experiment at large strain values. In accord with theory. these authors also found that the steady-state-shear viscosity was essentially the same as the suspending liquid viscosity.
