3rd International Workshop on Plasticity, Damage and Fracture of Engineering Materials, IWPDF 2023, İstanbul, Türkiye, 4 - 06 Ekim 2023, cilt.61, ss.3-11
Titanium alloys, due to their advantageous properties are used to construct key components in aero-engines. However, their susceptibility to dwell fatigue conditions has been known to lead to a severe reduction in functional life, necessitating a comprehensive understanding of the underlying micro-mechanisms. In order to examine this phenomenon, a rate dependent crystal plasticity (CP) model is coupled with a phase field fracture framework to simulate the nucleation and subsequent propagation of cracks in representative volume elements made up of HCP (hexagonal-closed packed) titanium grains. The evolution of damage is studied in both static and dwell loading conditions and crack nucleation at interactions between highly misoriented grains is analyzed. The numerical framework is found capable of simulating crack initiation and intra/inter granular propagation in crystal plasticity finite element (CPFE) simulations. The model is able to capture the load shedding phenomenon at soft-hard grain interactions under cyclic loading with dwell time. The majority of the damage is observed to be taken during the dwell period rather than during loading and unloading.