Biaxial Thermal Stress Fatigue and Crack Morphology

The experiment and numerical analysis of biaxial thermal stress fatigue under various stress ratio.The results show that the morphology of thermal fatigue cracks depend on both ratio of two principal stresses and ratio of two principal plastic stress, and the direction of straiight crack is perpendicular to the direction of maximum principal stress. Netty thermal fatigue crack will occurs when two principal stress and two principal plastic strains are approximately equal to each other.