A requirement for the safe design of thermoplastic parts is the ability to precisely predict mechanical behaviour by finite
element simulations. Typical examples include the engineering of relevant components in automotive applications. For this
purpose adequate material models are essential. In this context, the present work introduces a material modelling approach
for short fibre reinforced thermoplastics (SFRTPs). SFRTP parts are processed cost-effectively by injection moulding and
show a varying degree of anisotropy due to the locally inhomogeneous fibre distributions that arise during the moulding
process. The presented material model considers linear-elastic behaviour and non-linear orthotropic stress-state dependent
viscoplastic deformation for arbitrary fibre distributions. The constitutive equations are verified with the experiments
of a PPGF30 material regarding different stress-states and orientations.