Reliability Algorithms for Corrosion Fatigue

In this Phase II SBIR project, STI Technologies will team with APES Inc., with strong support from Lockheed-Martin Co. and Boeing Phantom Works, to develop an advanced predictive technology for USAF aging aircraft components subjected to corrosion-fatigue.The proposed work combines state-of-art stochastic modeling techniques with physics-based models of progressive corrosion-fatigue The final product of Phase II will be an integrated software system (Probabilistic Corrosion FAtigue, ProCORFA) that rapidlyperforms accurate component reliability and life-cycle cost analyses for military aging aircraft. To adequately approach the corrosion-fatigue damage phenomenon and take advantage of current USAF technology, ProCORFA will interface with ECLIPSE and AFGROWcodes. Phase I demonstrated the reliability algorithms for B707 lap joint design, including maintenance uncertainties (inspection, replacement and repairs). In Phase II, several aircraft component types subjected to different corrosion types will beinvestigated in detail. Based on the computed risks and maintenance event costs, an optimal-cost maintenance strategy for aging components can be determined. The ProCORFA software can also be used to compare different designs in terms of risks and costs,or to perform "what-if analyses" to evaluate the effects of different design and/or maintenance strategy modifications on component failure risks, remaining life and induced costs.