Constitutive Theory of fiber suspensions

Finally a mesoscopic background theory is discussed. In this approach a distribution of different fiber orientations and fiber deformations is assumed. The fiber orientation and deformation are additional variables in the domain of field quantities. The usual macroscopic fields of continuum mechanics are averages of mesoscopic fields over the different orientations and deformations. Macroscopic quantities characterizing the orientational order, the alignment tensors, and quantities characterizing fiber deformation, are defined by the help of the distribution function. They are internal variables in the macroscopic theory. The mesoscopic theory also demonstrates, that there is a skew symmetric part of the stress tensor in fiber suspensions.