A cyclic cohesive zone model is applied to characterize the fatigue crack growth behavior of a IN718 superalloy which is frequently\nused in aerospace components. In order to improve the limitation of fracture mechanics-based models, besides the predictions of\nthe moderate fatigue crack growth rates at the Parisââ?¬â?¢ regime and the high fatigue crack growth rates at the high stress intensity factor\nÃ?â?K levels, the present work is also aimed at simulating the material damage uniformly and examining the influence of the cohesive\nmodel parameters on fatigue crack growth systematically. The gradual loss of the stress-bearing ability of the material is considered\nthrough the degradation of a novel cohesive envelope. The experimental data of cracked specimens are used to validate the\nsimulation result. Based on the reasonable estimation for the model parameters, the fatigue crack growth from moderate to high\nÃ?â?K levels can be reproduced under the small-scale yielding condition, which is in fair agreement with the experimental results.
Loading....