Improved Life Cycle Management of Airborne Systems Tools

The Phase II of this program developed a computational fatigue software to simulate components with corrosion roughened surfaces. The goal of this proposed Phase II+ is to extend the computational fatigue software to simulate additive manufacturing (AM) products with as-produced surfaces. This will provide a rapid accept/reject criterion at the early design/manufacturing stage for certification of fatigue tolerant AM designs. The specific technology area to be investigated is the effect of the material microstructure, defects and surface roughness on the fatigue crack nucleation, short crack growth and long crack growth. The software is based on the physics of failure and this software module will be developed to explicitly model the geometry and strength of the microstructure, defects and surface roughness. It will predict the damage state (location, number and size of fatigue cracks) versus loading cycles. The tool will be calibrated and validated with laboratory fatigue tests of IN625 specimens with a statistically large number of tests performed by our OEM partner, Aerojet Rocketdyne and the predictions used to represent the large laboratory database that is traditionally used in the AM certification process. This will help create software that can be used by AM manufacturers.