Читать книгу The Rheology Handbook - Thomas Mezger - Страница 254

Creep (shear) compliance J(t) can be calculated using the following parameters: the preset shear stress τ0 and the resulting deformation function γ(t) obtained in the creep phase. Definition:

Equation 6.5

J(t) = γ(t) / τ0

Unit: [1/Pa = Pa-1].

The (shear) compliance is the reciprocal value of the shear modulus which can be imagined as rigidity then:

Equation 6.6

J = 1/G

The shape of the J(t)-curve is similar to the γ(t)-curve since for creep tests, the shear stress τ0 is preset as a constant value. Usually, J is presented on the y-axis, and time t on the x-axis (see Figure 6.9).

Figure 6.9: Creep compliance curves J(t), a) in the LVE range, b) outside the LVE range, showing comparatively higher J-values then