The Challenge - Tracking and predicting the progress of structural degradation with time requires one or more metrics for the severity of the environment the structure is experiencing. Traditional methods involve using stress and strain cyclic spectra to predict crack growth and/or crack nucleation, but in certain cases the environmental spectra (humidity, exposure cycles, corrosion rates, etc.) can be just as or more important in terms of its effects on structural degradation.

Engineered Solution - AP/ES provides traditional solutions that collect, analyze and break down the degratory components of cyclic spectra, i.e., reducing flight data recorder information and determining the regions of cyclic usage where the damage is most severe. These methods can be very useful in truncating fatigue test spectra to reduce test bay time, or for mission planning and fleet management to reduce the time spent flying harsh mission profiles. We also provide more involved solutions that characterize and include the environmental degratory structural effects, whether they involve environmental spectra derived from corrosion sensors, corrosion pitting rates, thickness loss rates, or other environmental metrics. Our techniques can include the important synergistic effects of stress cycles and environment as both act in time to degrade structural capability.