Читать книгу The Rheology Handbook - Thomas Mezger - Страница 253

At a selected temperature, the value of zero-shear viscosity is a material constant which can be determined using the following rheological test methods [6.6]:

1 Rotational tests: η0 as the limiting value of the shear viscosity function η( γ ̇ ) “at rest”, i. e. for γ ̇ → 0 (see Chapter 3.3.2.1a, Equation 3.1)

2 Frequency sweeps (oscillatory tests): η0 as the limiting value of the complex viscosity function η*(ω) “at rest”, i. e. for ω → 0 (see Note 3 in Chapter 8.4.2.1a, Equation 8.27)

3 Creep tests: η0 at the end of the stress phase, when reaching steady-state flow behavior.