After a thermal study, the temperatures are imported into a static study for thermal stress analysis. Simulation treats the thermal expansion or contraction of bolt connectors as follows.
Simulation prescribes to bolt connectors the same reference temperature at zero strain as for the rest of the assembly (T0) (see the static study's Flow/Thermal Effects tab).
For a loose fit bolt, the static study obtains the bolt temperature by averaging the temperatures of the head and nut contact surfaces. If the tight fit condition is enabled, the study also accounts for the temperature of the cylindrical hole surface when calculating the bolt temperature. Since the bolt connector shank is modeled as a beam element, the bolt connector can expand or contract only in the axial direction.
The length variation of the bolt due to temperature change is:
DL = Alpha * (T - T0) * L
where L is the bolt length and Alpha is the thermal expansion coefficient defined under Material in the Connectors PropertyManager.