|About this Abstract
||Materials Science & Technology 2011
||Fatigue and Microstructure: A Symposium on Recent Advances
||An Atomistic Energy-Based Model for Fatigue Accounting for Grain Boundary Characters
||Huseyin Sehitoglu, Michael Sangid, Hans J Maier
|On-Site Speaker (Planned)
Excessive scatter is observed in the fatigue response of a nickel-based superalloy, U720, which is partly attributed to the variability in the microstructure. Our approach is to model the energy of a persistent slip band (PSB) structure and use its stability with respect to dislocation motion as our failure criterion for fatigue crack initiation. The energies for dislocations creating slip interacting with the GBs, and nucleating/agglomerating within the PSB are computed via molecular dynamics simulations. Through this methodology, the fatigue life is predicted based on the energy of the PSB which is formulated with micro-mechanics concepts, which inherently accounts for the microstructure of the material. We account for distributions of grain size, orientation, neighbor information, and grain boundary character, which allows us to calculate fatigue scatter using a deterministic approach. The methodology is novel and should ultimately replace the empirical based fatigue modeling approaches that are been widely used today.
||Definite: A CD-only volume