Innovative Multi-scale/Multi-physics based Tool for Predicting Fatigue Crack Initiation and Propagation in Aircraft Structural Components using Phase

We propose to further develop the phase-field modeling and simulations we carried out in Phase I. Key focus of our research effort are enhancement phase-field models and computational strategies in order to make them applicable to more general, complex static and fatigue loading situations to predict crack initiation and growth in unified computational framework. Entire process of crack nucleation, short fatigue crack growth and large crack growth will be modeled and simulated as a continuous process using the phase-field method. Of particular interest in our Phase II work effort is the advancement of the phase-field model to 1) account for fatigue crack initiation and short crack growth within microstructure, 2) long fatigue crack growth including plasticity and 3D large-scale simulations, 3) coupled degradation mechanisms such as stress-corrosion cracking and corrosion fatigue, and 4) improve the computational efficiency by using advanced mesh adaptivity scheme and isogeometric finite element method. In this effort, we include the interaction of a growing short crack with heterogeneous microstructure of polycrystalline materials which can be suitably modeled with phase-field.