LUNA INNOVATIONS INCORPORATED — Department of Defense SBIR Phase I: Steel aircraft carrier hulls are subject to a variety of serious corrosion problems. Corro

Description

Steel aircraft carrier hulls are subject to a variety of serious corrosion problems. Corrosion and pitting take place on the interior surface of the hull where inspection is difficult or impractical. Additionally, exterior coatings may or may not impede the difficulty of launching acoustic energy in a hull due to steel"s high acoustic impedance compared to sea water. Exterior inspection requires a method capable of operating submerged, and of detecting pitting, thinning, and cracking throughout the hull thickness. Luna proposes an ultrasonic array technique that will be robust in the marine environment and fast enough for a practical survey of an entire hull. Key to the array technique is a signal processing method called time reversal analysis, which uses a stored model of"ideal"returns to emit a reverse-time signal that is very sensitive to defects in the hull under inspection, but tolerant of array alignment. Such an array may reach scan rates of a square meter in 10 seconds: quickly finding suspect regions needing detailed examination. The result will be a complete survey of the hull for pitting, thinning, and cracks, and storage of the hull state data for comparisons with prior and future surveys.