What is time temperature superposition rule?
The principle of time-temperature superposition states that the change in temperature from T to T0 is equivalent to multiplying the time scale by a constant factor aT which is only a function of the two temperatures T and T0.
What is a Mastercurve?
The master curve shows the time dependence (in terms of frequency) of the material at a constant reference temperature To; the temperature de- pendence of the viscoelastic properties is shown by the variation of the shift factor with tempera- ture.
What is temperature shift factor?
The temperature shift factor, aT, quantifies the horizontal shift between the compliance curves at different temperatures.
What is the use for WLF equation?
The WLF equation is typically used to describe the time/temperature behavior of polymers in the glass transition region. The equation is based on the assumption that, above the glass transition temperature, the fractional free volume increases linearly with respect to temperature.
What is asphalt master curve?
The master curve of an asphalt binder provides a relationship between the binder stiffness and reduced frequency over a range of temperatures and frequencies. To construct a master curve, the stiffness of an asphalt binder at multiple temperatures and frequencies is measured.
What is WLF shift factor?
The Williams–Landel–Ferry Equation (or WLF Equation) is an empirical equation associated with time–temperature superposition. Once constructed, the WLF equation allows for the estimation of the temperature shift factor for temperatures other than those for which the material was tested.
What is shift factor in WLF equation?
The amount of horizontal shift along the time axis is called the shift factor. If the Tg is chosen as the reference temperature, the shift factor for most amorphous polymers is given by the Williams-Landel-Ferry (WLF) equation (Williams et al., 1955).
What is viscoelastic deformation?
In materials science and continuum mechanics, viscoelasticity is the property of materials that exhibit both viscous and elastic characteristics when undergoing deformation. Viscous materials, like water, resist shear flow and strain linearly with time when a stress is applied.
What is a shift factor?
A shift factor to a particular line is the effect of this injection and withdrawal on the flow on the line. That is, the shift factor is the ratio of the change in the flow on a line to a change in the injection and a corresponding change in the withdrawal.
