A simple approach for adding thixotropy to an elasto-visco-plastic rheological model to facilitate structural interrogation of human blood

Abstract

• Simple thixotropic term introduced that allows thixo-elasto-visco-plasticity modeling. • Use of step up/down in shear rate experiments with human blood to fit parameters . • Use of oscillatory rheological experiments with human for model comparison. We demonstrate refinements of a simple elastic-viscous-plastic rheological model with the addition of a thixotropic term to better model rheological flow of human blood. The alteration of this model will contribute to better representation of lightly structured complex materials. The simple elastic-viscous-plastic (EVP) framework requires thixotropy for more accuracy in fitting and predicting the thixo-elasto-visco-plasticity of rheological flows with a microstructure. We demonstrate the performance of the added thixotropic features by comparing the TEVP construct to similar peer models using a cost function generated from predictions of rheological flows from triangle ramps to large amplitude oscillatory shear flow. To verify the efficacy of these thixotropic enhancements, the performance of the model is then measured against the other models with a penalty assessed based on number of model parameters. The framework holds the name “Enhanced Thixotropic-Elasto-Visco-Plastic” to reflect this methodology of adding thixotropy to the elastic-viscous-plastic capabilities of the standard construct.