Cold dwell fatigue analyses integrating crystal-level strain rate sensitivity and microstructural heterogeneity

On rate-dependent polycrystal deformation: the temperature sensitivity of cold dwell fatigue

A temperature and rate-dependent crystal plasticity framework has been used to examine the temperature sensitivity of stress relaxation, creep and load shedding in model Ti-6Al polycrystal behaviour under dwell fatigue conditions. A temperature close to 120°C is found to lead to the strongest stress redistribution and load shedding, resulting from the coupling between crystallographic slip rate...

Probabilistic sensitivity analysis of dwell-fatigue crack initiation life for a two-grain microstructural model

Crack initiation in Ti-6242 has been observed to occur in a grain with a hard orientation for basal slip neighbouring a grain with a soft orientation. Because there is significant variability in microstructural features and crack initiation life, it is useful to explore the effects of the variability of the microstructural components through a probabilistic sensitivity analysis. In this paper, ...

Mean Strain Effects and Microstructural Observations during In-vitro Fatigue Testing of Niti

The non-linear nature of the superelastic phase transformation in NiTi means that conventional fatigue life theory is difficult to apply. The volume fraction of martensite/parent phase and its role in the fatigue mechanism is not understood. This paper considers the fatigue life of superelastic NiTi alloys when tested at 2Hz in Ringers solution. In agreement with other researchers [1] [2] it wa...

Mechanical Characteristics and Failure Mechanism of Nano-Single Crystal Aluminum Based on Molecular Dynamics Simulations: Strain Rate and Temperature Effects

Besides experimental methods, numerical simulations bring benefits and great opportunities to characterize and predict mechanical behaviors of materials especially at nanoscale. In this study, a nano-single crystal aluminum (Al) as a typical face centered cubic (FCC) metal was modeled based on molecular dynamics (MD) method and by applying tensile and compressive strain loadings its mechanical ...

Model of fatigue damage in strain-rate-sensitive composite materials