Multi-scale modeling and experimental validation for component fatigue life prediction

A fatigue failure prediction procedure is discussed based on a two scale micro meso mechanical model for metallic structures. This model predicts the fatigue life and accounts for physical quantities like the mean stress effect in high cycle fatigue. Another model developed at meso-scale level with BCJ (Bammann, Chiesa and Johnson, 1996, Theoretical and Applied Mechanics, Tatsumi, Watanabe and Kambe (Editors), 359-376) internal state variables, is used to predict progressive damage in ductile materials. This meso-scale model is incorporated within the general purpose finite element software ABAQUS through a user subroutine VUMAT. A lug joint specimen is simulated using the BCJ model modified for fatigue and the location of the crack initiation sites is found. Experiments are conducted with the lug joint specimen under fatigue loading and the models are validated for the fatigue life prediction and location of the damage sites.