A plot of the shear stress versus the shear rate for a fluid.
[rheo- + G. gramma, something written]
References in periodicals archive ?
Main step in the data processing procedure include calculating the shear stress as a function of radial position in the pipe, processing the velocity profile image to obtain a velocity profile, calculating the shear rate as a function of radial position from the velocity profile, and generating the rheogram by plotting the shear stress against the shear rate (Arola et al., 1997, Callaghan 1999 and Tozzi et al., 2012).
The rheogram observed with an increase in shear rate differed from that observed with a decrease in shear rate, and a hysteresis loop was observed for all ointment formulations.
Marked points represent the average values of the rheogram experimental data and continuous lines are the fit results calculated using the Herschel-Bulkley model.
Nadkarni, "From melt flow index to rheogram," Rheologica Acta, vol.22, no.1, pp.
In Newtonian fluids, shear stress and shear rate are directly proportional (N = 1), so the rheogram will be a straight line, while, in non-Newtonian fluids, there is not a direct relationship between them (N > 1) 17].
For the Brookfield rheometer, the viscosity of the same samples has been obtained, directly from the rheogram of the oils and independent of the velocity.
The rheogram of Thixotropy obtained by plotting shear stress versus shear rate shows the down curve (obtained by decreasing shear rate) is displaced to the left of the up curve (obtained by increasing shear rate).
For drawing the rheogram, shear rate was increased for the samples till maximum.
For a plastic material, the rheogram does not pass through the origin, and no strain rate occurs until the shear stress exceeds some yield value.
The minimal elastic torque time of the MDR rheogram for each compound was collected and is hereafter designated as [t.sub.MIN].