The response of simple fluids to a high shear rate is investigated via the molecular dynamics technique with the model system of 108 Lennard-Jones particles simulating Ar liquid near its triple point.
The stress-strain response of the system shows non-linear behavior to the applied shear strain, which may be related to the non-linear structural relaxations of higher order distortions in the radial distribution function. To invoke this point of view the possible dependence of the response function on the built-up stress is examined.
It is also found that the flow is made easier by the presence of stress built up in the liquid.
