Oscillatory squeezing flow of a biological material

Abstract

Large-amplitude oscillatory squeezing flow data are reported for a complex biological material, which is highly shear-thinning in oscillatory shear flow. This soft tissue has a linear viscoelastic limit at a strain of approximately 0.2%. The oscillatory squeezing flow data at large strain are analyzed using two constitutive models: a bi-viscosity Newtonian model, and a non-linear Maxwell model. It is found that although both models may have the same response in shape, the later matches with our non-linear experimental data better. It is also concluded that the non-linear response of the material in large amplitude oscillatory flow is mainly due to the shear thinning of the material.