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THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
GEORGIA INSTITUTE OF TECHNOLOGY
Under the provisions of the regulations for the degree
DOCTOR OF PHILOSOPHY
on Monday, October 22, 2018
1:55 PM
in MRDC 3515
will be held the
DISSERTATION PROPOSAL DEFENSE
for
Adrienne Muth
"Advanced Structure-Property Linkages Based on Extreme Value Statistics for Fatigue Indicator Parameters for Alloys"
Committee Members:
Prof. David McDowell, Advisor, MSE
Prof. Surya Kalidindi, MSE
Prof. Richard Neu, ME
Prof. Reji John, Air Force Research Lab
Prof. Adam Pilchak, Air Force Research Lab
Abstract:
Fatigue lifetime is a critical performance requirement for polycrystalline metal alloys used in aerospace applications but is a significant challenge to study, as fatigue behavior exhibits highly variable responses to microstructure attributes and loading conditions. Elucidating the role that combinations of microstructure attributes play in promoting fatigue crack formation and early growth requires a prohibitive number of experiments. Identifying the local microstructure states that favor fatigue crack formation and, separately, early crack growth will allow for materials processing to be adapted to minimize risk of crack initiation. In the proposed work, a hierarchical, multiscale, statistically-driven computational workflow is laid out to provide a template for using data science methods to enhance investigation fatigue response of polycrystalline alloys, using Ti-6Al-4V as an example.
First, microstructure data from experimental results are used to create statistically representative microstructure volumes, which are then subjected to cyclic loading using a constitutive model that captures crystallographic slip using finite element modeling. Fatigue Indicator Parameters (FIPs) are investigated as surrogate measures of driving force for fatigue crack formation within the nucleant phase or grain and characterized by the phase of the grain in which they are located. The proposed project will utilize these FIPs and methodology to provide insight for improved fatigue resistance behavior for both fatigue crack formation and growth past first barrier. Significance of the work includes:
