Store/Aircraft Interface Force Measurement System

Naval air platform stores include various payloads including ordinance. Fatigue induced failures can occur without warning at the interface between the payload and the airframe hardpoints. There is currently no systematic means of monitoring, recording, and tracking the forces which lead to fatigue and eventual catastrophic failure of the store hangers or their attachment points. A system of sensors is required to accurately measure transmitted forces and moments that will be fed into a predictive fatigue model for these components. Acceleration measurements cannot be used to explicitly measure forces and moments that are required for use in predicting cumulative fatigue damage. Additionally, direct strain measurements are difficult to correlate to transmitted forces and moments due to placement and orientation sensitivity, as well as averaging errors that occur due to measurement of strain gradients. Direct measurement of the transmitted forces and moments is required. Our solution is focused on innovative sensor placement across all load axes combined with using the deformations that occur across the store interface structure in response to applied loads, in order to measure force and moment time histories. Macro Fiber Composite (MFC) piezoelectric smart materials will be assessed for the primary sensor element.