# Prediction of primary normal stress difference from shear viscosity data using a single integral constitutive equation

@article{Wagner1977PredictionOP, title={Prediction of primary normal stress difference from shear viscosity data using a single integral constitutive equation}, author={Manfred H. Wagner}, journal={Rheologica Acta}, year={1977}, volume={16}, pages={43-50} }

SummaryBased on a single integral constitutive equation with a strain-dependent memory function, a relation between the primary normal stress functionθ and the shear viscosity functionη is proposed. According to this theory, the primary normal stress functionθ can be obtained from viscosity data by simple differentiation of the viscosity functionη with respect to the shear rate
$$\dot \gamma$$
, and multiplication by a factor (−1/n). The material parametern is thereby associated with the strain… Expand

#### 83 Citations

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