Life prediction based on fatigue-environment damage under multiaxial thermo-mechanical loading.

• The competition between protective and harmful effects of oxidation is revealed. • A high-temperature environmental damage model is proposed. • A mechanism based multiaxial thermo-mechanical fatigue life model is proposed. • The normal mean stress and cycle period are used to express competition mechanism. • The temperature dependence of material damage is quantitatively described. In this paper, the competition mechanism between protectiveness and harmfulness of oxidation, as well as the effects of cycle period, mean stress and temperature on the damage behavior of TA15 titanium alloy are revealed under multiaxial thermo-mechanical fatigue loading. Based on the damage mechanism, a high-temperature environmental damage model is proposed under multiaxial thermo-mechanical fatigue loading first, then a life prediction method is developed by combining a multiaxial fatigue damage model. The experimental verification results under uniaxial and multiaxial thermo-mechanical fatigue loadings showed that almost all of the prediction errors are within a factor of 2. [ABSTRACT FROM AUTHOR]