Читать книгу The Rheology Handbook - Thomas Mezger - Страница 247

In order to explain the analysis in detail, the creep curve (from t0 to t2) and the creep recovery curve (from t2 to t4) are divided into the following sectors, see Figure 6.8:

1 Δγ1 = (γ1 – 0) = γ1 as step-like, purely elastic change in deformation occurring immediately after the beginning of the test, idealized: “without any time delay, in zero-time” (behavior of spring S1)

2 Δγ2 = (γ2 – γ1) as delayed viscoelastic change in deformation (spring S2 together with dashpot D2)

3 Δγ3 = (γ3 – γ2) as purely viscous change in deformation (dashpot D3); after reaching steady-state behavior, i. e. a constant rate of deformation (or shear rate), the γ-curve is showing a constant slope angle β then

4 γmax = Δγ1 +Δγ2 + Δγ3 = γ3 is the maximum deformation, at the end of the stress phase

5 Δγe = (γmax – γv) is the change in deformation as re-formation in the creep recovery phase (representing the elastic proportion of the viscoelastic behavior)

6 γv is the extent of remaining deformation after the creep recovery phase (viscous proportion)