Predictive Lifing Tool for Coupled Corrosion, Pitting, and Fatigue Degradation

The US Navy has an increasing need for predictive lifing capabilities, particularly as they pertain to corrosion, fatigue, and their complex interconnected mechanisms. Current empirical methods for lifing critical propulsion components under these coupled conditions are limited in their applicability, and often lead to premature sustainment activities that leave unused safe operational life on the table. VEXTEC proposes to build on its commercialized software VPS-MICRO® by incorporating corrosion effects on performance of common Naval alloys (one aluminum alloy, and one stainless steel alloy). VPS-MICRO is a fatigue durability prediction and risk assessment software, which utilizes probabilistic, physics-based mechanistic modeling. The Phase I Base program will show the feasibility of linking appropriate corrosion modeling schemes (for pre-existing corrosion features like pits, surface cracks, and near-surface cracks) to VPS-MICRO. Phase I Option program will involve architecting the individual analysis modules into a computational protocol, such that the corrosion analysis and the subsequent fatigue analysis simulations can be set as a standard, repeatable and reliable set of steps. VEXTEC will collaborate with Dr. James Burns, a recognized expert in corrosion fatigue testing and modeling, to understand corrosion’s role in creating these roughness conditions.