AN INTELLIGENT ULTRASONIC INSPECTION SYSTEM FOR FLOODED MEMBER DETECTION IN OFFSHORE STRUCTURES

This paper describes an ultrasonic system for automatic underwater ins pection of steel jacket offshore installations. It is based on the una mbiguous detection of water ingress in normally sealed tubular members , thereby providing an indication of through wall structural failure. A novel transducer design, based on a dual frequency array of 1-3 conn ectivity thickness drive transducers, is used to provide required sens itivity and act also as an environmental monitor for input to an exper t system, which performs automatic data analysis. Although intended pr imarily for operation on a remotely operated vehicle, the system may b e employed satisfactorily by a diver. A series of test trials are desc ribed and the prototype is shown to perform very well for all intended modes of operation.