The Thermoelastic damping Qted should be specified either as a
User defined value, or as the thermoelastic damping contribution straight from the solid mechanics interfaces, when you add a
Thermal Expansion subnode (with the Structural Mechanics Module). In the latter case it is defined by
where S is the second Piola-Kirchhoff tensor and
α is the coefficient of thermal expansion.
Physics tab with Solid selected in the model tree: