VEXTEC Corporation — Department of Defense SBIR Phase I: AF151-121

Description

ABSTRACT:The SBIR primary objective will be to show the feasibility of advance modeling for simulating and predicting the surface corrosion leading to fatigue damage. This capability will produce early-life stage models which will enhance state of the art corrosion analysis. The SBIR conceptual modeling method must address small damage, in a corroded microstructure for fatigue crack growth. The method must predict the random field of the size and location of the corrosion pits and transition of pits to cracks. The method must be able to model subsequent the crack propagation. Finally, the method must be simple enough for wide acceptability and deployable with standard test techniques for wide application.BENEFIT:The model will be capable of conducting sensitivity analysis on the results to allow for identification of those microstructural features (such as distribution of pit depth and population density) most effecting fatigue life. It must be noted that VEXTEC has applied its probabilistic microstructural models to successfully predict fatigue damage accumulation in a variety of materials under various damage mechanisms. The models will be inherently mechanistic and model the prevalent damage mechanisms under the appropriate conditions. This SBIR will extend the model capability to explicitly include corrosion surface fatigue. A Phase I success will be the demonstration of the described technique to predict cracks in a corrosion fatigue test specimen.