  Accurate predictions of thermo-mechanically coupled process in metals can
lead to a reduction of cost and an increase of productivity in manufacturing
processes such as forming. For modeling these coupled processes with the finite
element method, accurate descriptions of both the mechanical and the thermal
responses of the material, as well as their interaction, are needed.
Conventional material modeling employs empirical macroscopic constitutive
relations but does not account for the actual thermo-mechanical mechanisms
occurring at the microscopic level. However, the consideration of the latter
might be crucial to obtain accurate predictions and a complete understanding of
the underlying physics. In this work we describe a fully coupled implicit
thermo-mechanical framework for crystal plasticity simulations. This framework
includes thermal strains, temperature dependency of the crystal behavior and
heat generation by dissipation due to plastic slip and allows the use of large
deformation steps thanks to the implicit integration of the governing
equations. Its use within computational homogenization simulations allows to
bridge the plastic deformation and temperature gradients at the macroscopic
scale with the microscopic slip at the grain scale. A series of numerical
examples are presented to validate the approach.
