Abstract: Using the dissipated energy as an essential parameter,the energy dissipative structure in pro- cess of fatigue damage of materials has been established.Through thermodynamic analysis for irreversible energy dissipation in fatigue damage process,the heat dissipative variations in cyclic loading process as well as in a cycle have been systematically studied on the basis of low cycle fatigue tests and infrared measurement of self-heating thermography.Meanwhile,the cyclic hysteresis energy and efficient energy dissipation (stored energy) have been proposed during fatigue damage process.

Key words: fatigue damage, energy dissipation, cycle loading process