Stress assessment and fatigue behavior evaluation of components with defects based on the finite element method and lock-in thermography

摘要

The relationships between the stress concentration factors K(t)s to the depths h and diameters phi of blind holes were investigated based on the finite element method. The E-Mode, built-in the lock-in thermographic technique, was used to determine the stress distribution around blind holes and to predict the variation of K(t)s. Good predictions were achieved between the thermography and finite element method. The Altair Li software and Altair software were, separately, used to study the variations of the intrinsic dissipation and temperature increment during fatigue process for the purpose of damage status analysis. These two signals were considered as fatigue damage markers to rapidly predict the fatigue limits of components with different blind holes and then to determine the fatigue notch coefficient K-f. Theoretical results validate the capability of the lock-in thermography for fatigue evaluation.