In the above expressions, s
is the shear stress, g0 is the viscosity,
and j c_
¼
j is the L2 norm of the symmetric rate-of-strain tensor. The
Bingham equation follows a Newtonian behaviour above the yield
stress. As the matrix is a thermoplastic polymer, the fluid regime
should exhibit a shear thinning behaviour. Nonetheless, in the first
attempt at determining a shear thinning Carreau behaviour for this
complex ROS material, the yield effect proved to be a first order
phenomenon [30]. Thus, in this paper, the most simple viscoplastic
behaviour (Eq. (1)) is tried to reproduce the plateau.