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Opportunity at Air Force Research Laboratory (AFRL)

Probabilistic Life Prediction of High Temperature Metals

Location

Materials & Manufacturing, RX/Structural Materials Division

RO# Location
13.25.05.C0324 Wright-Patterson AFB, OH 454337817

Advisers

name email phone
William David Musinski william.musinski.1@us.af.mil 937-255-0485

Description

The research focus is to develop a comprehensive understanding of relevant damage initiation, accumulation mechanisms and failure of aerospace structural metallic alloys and develop next-generation validated damage evolution and probabilistic fatigue life prediction methodologies necessary for forecasting durability and reliability during service. Specific topics of interest include: (1) microstructure-sensitive probabilistic fatigue and damage tolerance models, with emphasis on life-limiting properties, (2) initiation, microstructure-scale (small) crack growth and continuum-scale (long) crack growth under service loading conditions such as fatigue, dwell-fatigue and thermal-mechanical fatigue loading, (3) 3-dimensional crack growth and advanced fracture mechanics, including microstructure-scale (small) crack growth and continuum-scale (long) crack growth, (4) high fidelity microstructure-sensitive constitutive models for use in 3-dimensional simulation of damage accumulation in actual microstructures, (5) advanced micro- and macro-mechanics experimentation including microstructure-scale deformation mapping, multi-scale (microscale, milliscale and conventional) specimen testing under uniaxial and multi-axial loading conditions, and (6) influence of surface treatments such as peening (e.g. shot peening, laser shock peening etc.) and stress concentration sites such as holes on fatigue life and damage tolerance. Models emphasizing mechanism-based approaches for reduction in uncertainty, Bayesian methods and independent validation of predictive capabilities are of interest to us. We are seeking Integrated Computational Materials Science and Engineering (ICMSE) based multi-scale approaches and models that can be used to probabilistically predict location specific properties in geometrically complex components with nominally uniform or gradient microstructures/chemistries. Specific materials of interest include, but not limited to, Titanium alloys, Nickel-base superalloys, additively manufactured metals, and functionally graded and joined metals. Specialized high temperature testing capabilities, material characterization facilities and significant computational resources are available for multi-scale experiments and computations.

References:

[1]  Golden, P.J.,  Whitney-Rawls, A., Jha S.K., Porter III, W.J., Buchanan, D., Prasad, K., Chandravanshi, V., Kumar, V., John, R., Probabilistic prediction of minimum fatigue life behavior in alpha + beta titanium alloys.  Fatigue Fract Eng Mater Struct, 42, 674-685, 2019.

[2]  Turner, T.J., Shade, P.A., Bernier, J.V., Li, S.F., Schuren, J.C., Kenesei, P., Suter, R.M., Almer, J., Crystal plasticity model validation using combined high-energy diffraction microscopy data for a Ti-7Al specimen, Metall and Mater Trans, 48A, 627-647, 2017.

Keywords:
3-Dimensional; Crack growth; Fatigue; Life prediction; Microstructure; Model; Probabilistic; High Temperature; Metals

Eligibility

Citizenship:  Open to U.S. citizens
Level:  Open to Postdoctoral and Senior applicants

Stipend

Base Stipend Travel Allotment Supplementation
$76,542.00 $4,000.00

$3,000 Supplement for Doctorates in Engineering & Computer Science

Experience Supplement:
Postdoctoral and Senior Associates will receive an appropriately higher stipend based on the number of years of experience past their PhD.

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