On material interfaces in thermomechanical solids

This contribution derives thermodynamically consistent balance equations for material interfaces in thermomechanical solids. Thereby, both displacement and temperature jumps are admissible. To this end, the interface is equipped with its own thermodynamic life, i.e. we assume separate interface free energy, entropy and the like. The thermodynamical admissibility then follows from proper definitions of the interface displacement and the interface temperature, whereby in particular, the latter follows in an unexpected format. The formulation is exemplified for the example of thermoelasticity.