# 15.18. Thermo EP Power Model

Output variables available for this model are listed in Table 15.18.1.

Table 15.18.1 State Variables for THERMO EP POWER Model
Index | Name | Description
--- | --- | ---
1 | `EQPS` | equivalent plastic strain
2 | `RADIUS` | radius of yield surface
3 | `BACK_STRESS_XX` | back stress - xx component
4 | `BACK_STRESS_YY` | back stress - yy component
5 | `BACK_STRESS_ZZ` | back stress - zz component
6 | `BACK_STRESS_XY` | back stress - xy component
7 | `BACK_STRESS_YZ` | back stress - yz component
8 | `BACK_STRESS_ZX` | back stress - zx component