Results for Rigid and Elastic Dumbbells

In the preceding sections many results have been presented for the bead-rod (rigid dumbbell) suspensions these results were obtained by solving the equation for the distribution function and then calculating the components of the stress tensor. It was pointed out in Eq. (4.23) for bead-spring (Hookean dumbbell) suspensions, that there is a constitutive equation which can be used to calculate the stresses directly without any need for finding the distribution function. Hence obtaining the Hookean dumbbell suspension results presents no difficulty. 

In Table 3 we summarize the expressions for the material functions for the various experiments discussed in Parts II, III, and IV. The rigid dumbbells seem to give results which are in qualitative agreement with experiment, whereas the elastic dumbbells do not. Specific points of difference are  

In steady-state shear flow the rigid dumbbells give a shear-rate dependent t] and 6, whereas these non-Newtonian effects are absent for the elastic dumbbells. 

In small-amplitude oscillatory motion, the rigid dumbbells give a non-zero high-frequency asymptote for t] whereas the elastic dumbbells do not. 

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