  Numerous models have been developed in the literature to simulate the
thermomechanical behavior of amorphous polymer at large strain. These models
generally show a good agreement with experimental results when the material is
submitted to uniaxial loadings (tension or compression) or in case of shear
loadings. However, this agreement is highly degraded when they are used in the
case of combined load cases. A generalization of these models to more complex
loads is scarce. In particular, models that are identified in tension or
compression often overestimate the response in shear. One difficulty lies in
the fact that 3D models must aggregate different physical modeling, described
with different kinematics. This requires the use of transport operators complex
to manipulate. In this paper, we propose a mechanical model for large strains,
generalized in 3D, and precisely introducing the adequate transport operators
in order to obtain an exact kinematic. The stress strain duality is validated
in the writing of the power of internal forces. This generalized model is
applied in the case of a polycarbonate amorphous polymers. The simulation
results in tension/compression and shear are compared with the classical
modeling and experimental results from the literature. The results highly
improve the numerical predictions of the mechanical response of amorphous
polymers submitted to any load case.
