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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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via
BlueJeans Video Conferencing
https://bluejeans.com/396605134
will be held the
DISSERTATION DEFENSE
for
Adrienne Muth
"A Large Scale Computational Study of Fatigue Hot-spots"
Committee Members:
Prof. David McDowell Advisor, ME/MSE
Prof. Surya Kalidindi ME/MSE/CSE
Prof. Richard Neu ME/MSE
Reji John, Ph.D., AF Research Lab, Materials and Manufacturing Directorate
Adam Pilchak, Ph.D., AF Research Lab, Materials and Manufacturing Directorate
Abstract:
Formation of a fatigue crack at the subgrain scale is a statistically rare event, as plastic deformation at the microscale ranges from highly heterogeneous at low strain to homogeneous at high strain. Fatigue Indicator Parameters (FIPs) for Ti-6Al-4V are computed using crystal plasticity finite element modeling of uniaxial cyclic straining of ensembles of statistical volume elements for a range of distinct microstructures at several strain amplitudes and mean strain conditions. The selection of FIPs is informed by prior experimental studies. The sites of extreme value (EV) FIPs that are most likely to form and grow a fatigue crack are identified in these simulations, and 2-point spatial correlations are applied to investigate the higher dimensional influence of microstructure attributes in the neighborhood of these fatigue hot-spots. To reduce the high dimensionality of the associated 2-point correlations, principal component analysis is applied. A reduced-order model using an artificial neural network is used to classify EV FIP locations based on these neighborhood spatial correlations.
