| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Processing-Microstructure-Property Relationships of Titanium and Titanium Alloys
|
| Presentation Title |
Microstructure-based Equivalent Initial Flaw Size (m-EIFS) Distributions for Airframe Structural Components |
| Author(s) |
Adam L. Pilchak, Manisha Banker, Michelle Harr, Joshua Shaffer, Thomas Carmody, Nathan Crosby, Juan Ocampo, Harry Millwater, Ayman Salem |
| On-Site Speaker (Planned) |
Adam L. Pilchak |
| Abstract Scope |
The damage tolerance sustainment philosophy was introduced in the late 1970’s. A key parameter in this methodology is the equivalent initial flaw size (EIFS). While the approach has proven successful, it has failed in certain cases where micromechanical phenomena overshade continuum mechanics. One such example is the case of beta-annealed titanium alloys which exhibit coarse lamellar microstructures with large colony sizes. In such situation small crack effects may persist to physically large crack sizes. Here we demonstrate a mechanism-based methodology for establishing an initial flaw size distribution from microstructure characterization data that is segmented based on observed fatigue damage mechanisms and which can be used in fatigue life prediction of beta-annealed titanium alloys. The approach is demonstrated within the probabilistic damage tolerance code SMART | DT and represents an improvement over existing fracture mechanics methods which may lead to anticonservative predictions. |