You can define the heat generation some part of FFlex body. Heat generation is nothing but conversion of one form of energy (like electrical, chemical, or nuclear energy) into thermal energy (heat energy) inside a FFlex body.
Figure 1 HeatGen. icon of the FFlex group in the Flexible tab
Figure 2 Heat Generation dialog box
•Element Set: Select an element set to define heat generation.
•Expression
•Heat generation: Define the expression for heat generation.