Effect of Parameter Accuracy and Variance on Structural Life Prediction and Life-cycle Costs

Systems & Electronics, Inc (SEI) proposes a program of research study for quantifying the effect of parameter accuracy and variance on structural life prediction and life-cycle cost of airframe structural details. In particular, parameters related to thestructural configuration, material types, flaw geometry, component tolerances and loading regime will be studied and the significance of variations in these parameters affecting estimated life, cost of inspection and repair will be quantified. The maintasks of SEI's proposal include: (1) conduct a comprehensive review of current life protection models; (2) select two types of structural details and conduct an analysis of parameter accuracy and variation for these details; (3) integrate aircraftlife-cycle cost and aircraft availability models with life prediction analysis model; (4)recommend modification in design and life prediction methods; (5)conducting a trade-off study to determine the benefit-cost associated with future research areas inlife estimation methods; (6)prepare directions for research in Phase II and commercialization plan for Phase III; and (7)prepare a final report. The proposed research has a great deal of military and commercial applications in the areas related to fatiguedamage and life expectancy evalution of aircraft components.The results from this research is expected to provide a more refined method of crack growth fatigue life prediction for aircraft components. Immediate application of the research will be formilitary and commercial aircraft. The findings from this research will link the variation and accuracy in design parameters to cost and aircraft availability. This is expected to reduce aircraft operations and service cost.