Rapid Inspection of Aluminum Hulls Below the Waterline Using Ultrasonic Guided Waves

An ultrasonic guided wave phased array approach is proposed for the rapid inspection of aluminum ship hulls below the waterline. With the proposed guided wave phased array technology, a centralized probe is used to steer a beam of ultrasonic energy around the hull structure, like radar. The gathered data can then be used to construct an image of the inspected region. The work to be completed in the Phase I effort would address the selection of the optimal guided wave mode/frequency for aluminum hull geometries as well as the type of probe needed to generate said mode/frequency. The proposed technique would be thoroughly evaluated for the detection of corrosion and cracking damage in the hull structure. A Phase I Option effort would investigate alternative array geometries, begin the development of a software package, and review potential technology deployment methods such as robotics. Northrop Grumman Shipbuilding has agreed to provide access to similar hull structures if available and to provide information regarding typical hull geometries and constructions practices. A Phase II effort would transition the developed technology from the lab to actual hull structures.