691270.fig.004a
(a)
691270.fig.004b
(b)
691270.fig.004c
(c)
691270.fig.004d
(d)
Figure 4: Various linear viscoelastic models, where 𝜂 is the Newtonian viscosity, 𝐸 is the elastic modulus, 𝑢 is the approach and 𝐹 is the applied external remote load.