Magnetoelastic Fiber-Filled Appliqué for Detecting Structural Damage

A new appliqué is proposed consisting of a film filled with stress sensitive magnetic fibers. This film, applied over the structure, can be imaged to measure stress concentration and/or anomalies resulting from an impact. This would be a valuable tool to provide warning of structural distress/damage. This proposal will design the appliqué, evaluate two different readout systems for measuring the strain measurements and select and demonstrate measurements on the selected approach. The appliqué will use polymer filled with small diameter magnetoelastic fibers, with the readout made with either a microwave scanning system based on reconstruction of the stress sensitive dielectric profile or an inductive coupled detector, using the fibers formed into small loops. The Phase 1 will select the most promising of these two advanced readout techniques and also do preliminary experiments, primarily on fill of the magnetic fiber and required stiffness of the appliqué so it can detect and remember the damage.