Large Scale Orientation - The Need for a Finite Strain Tensor

1 Large Scale Orientation - The Need for a Finite Strain Tensor 

The relaxation processes described above apply to linear viscoelastic behavior. If the deformation is not small or slow, the orientation of the chain segments may be sufficiently large to cause a nonlinear response. We will see that this effect alone can be accounted for in rheological models by simply replacing the infinitesimal strain tensor by one able to describe large deformations no new relaxation mechanism needs to be invoked. Nonlinear effects related to orientation, such as normal stress differences, can be described in this manner. 

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