Experimentally validated dwell and cyclic fatigue crack nucleation model for α-titanium alloys

This paper develops an experimentally calibrated and validated crystal plasticity finite element model with a probabilistic crack nucleation model for predicting dwell and cyclic fatigue crack nucleation in polycrystalline microstructures of titanium or Ti alloys. The nucleation model accounts for load-shedding due to time-dependent plastic flow and variability in crystal strength. The predictions are corroborated with experimental observations of nucleation times for dwell and cyclic loading. Experimental characterization of failed samples reveal that crack initiation on (0001) planes are highly inclined away from the stress axis. The probability distribution of simulated facet orientations are in agreement with experimentally measured orientations. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.