Techniques and Models to Relate Useful Life Remaining Predictions to Detectable Fault Conditions in Mechanical Systems

"Systems Planning and Analysis, Inc. (SPA) proposes to expand upon our Remaining Useful Life Estimation (RULE) algorithm as a means of predicting the remaining useful life of fatigue limited components on the Joint Strike Fighter (JSF). By accuratelypredicting the remaining useful life of a component, the U.S. Navy will be able to keep parts in service longer, thereby saving substantial operating costs without sacrificing safety. The RULE algorithm uses regime recognition or usage monitoring data asan input into a Monte Carlo simulation based technique that allows for the prediction of the remaining useful life of a particular component with a known reliability. Standard Navy practices dictate that a component operates for a set number of hoursbefore retiring that component. Based on the predicted aircraft usage, test flight measured load data, and experimentally measured fatigue data, the fatigue life is set such that the part has a known reliability. Using the RULE methodology, thecomponent can be flown until a certain percentage of the fatigue life is consumed, while retaining the desired reliability of the current technique. SPA's Phase I SBIR program focuses on using the RULE methodology on the JSF and experimental validation ofthe technique. The RULE methodology has applicability in any application where critical components are replaced on a regular basis becuase of fatigue. The most direct application of the technology