Project Description

Polycrystalline alloys form the backbone of critical infrastructure for the energy, defense, and transportation sectors. In these structural alloys, fatigue is the critical failure mechanism. Traditionally, the lifetimes of these materials are based on overly conservative approaches based on statistical regressions through empirical data. Through physics-based modeling, the fatigue life, in terms of crack initiation and short crack propagation, can be determined. The physics-based approaches offer substantial benefits compared to traditional methods, including reducing the time and cost to introduce new materials and processing routes into application and providing the framework for more informed decision making by connecting materials considerations with design, manufacturing, and in-service use. This project will use crystal plasticity modeling on virtual microstructures to predict fatigue life. The project will compare to existing in situ datasets of 3D bulk alloy behavior from multimodal high energy X-ray imaging techniques. Opportunities exist to extend fatigue damage mechanisms to include environmental effects, including oxidation and grain boundary sliding.  

Start Date

2024 (earlier in the year is preferred)

Postdoc Qualifications

PhD in Computational Solid Mechanics and Background in Microstructure of Alloys 

Co-Advisors

Michael D. Sangid, msangid@purdue.edu, School of Aeronautics and Astronautics, Professor, Website: https://engineering.purdue.edu/~msangid/

Thomas H. Siegmund, siegmund@purdue.edu, School of Mechanical Engineering, Professor, Website: https://engineering.purdue.edu/MYMECH 

Short Bibliography

[1] Gopalakrishnan S, Bandyopadhyay R, Sangid MD, “A framework to enable microstructure-sensitive location-specific fatigue life analysis of components and connectivity to the product lifecycle,” International Journal of Fatigue 165 107211 (2022).
[2] Bandyopadhyay R, Sangid MD, “A probabilistic fatigue framework to enable location specific lifing for critical thermo-mechanical engineering applications” Integrated Materials and Manufacturing Innovations, 10 20-43 (2021).
[3] Ravi P, Naragani D, Park JS, Kenesei P, Sangid MD, “Direct observations and characterization of crack closure during microstructurally small fatigue crack growth in additively manufactured IN718 via in-situ high-energy X-ray characterization,” Acta Materialia 205 116564 (2021).
[4] Prithivirajan V, Ravi P, Naragani D, Sangid MD, “Direct comparisons of microstructure-sensitive fatigue crack initiation via crystal plasticity simulations and in situ high energy X-ray experiments,” Materials and Design 197 109216 (2021).
[5] Bandyopadhyay R, Prithivirajan V, Peralta AD, Sangid MD, “Microstructure sensitive critical plastic strain energy density criterion for fatigue life prediction across various loading regimes,” Proceedings of the Royal Society A 476 2236 (2020).