Hi Teng,

From my understanding, it might not be possible to properly determine thermal stresses without employing a thermal solver. The MAT 224 model provides a simplified technique to calculate temperature rise without a full thermal analysis by assuming a portion of plastic work at each element is converted to heat (using the BETA variable). While it alleviates the need for fully coupled thermo-mechanical analysis, it is best suited for modeling deformation at dynamic strain rates where adiabatic or semi-adiabatic condition prevails and an estimate of temperature rise is needed.