UIT benefits of ultrasonic technology for high cycle fatigue of offshore infrastucture management


Structural integrity and fatigue are primary concerns in design and construction of offshore floating production facilities, both in new builds and conversions. Cyclic loading affects high cycle fatigue prone areas such as hull connections, mooring equipment, crane pedestals, and flare structures on floating units. Most offshore and marine classification societies require that the fatigue design not only meet or exceed life of the field, but also employ a fatigue life factor of safety for critical connections. Applied Ultrasonics offers a cutting edge method to extend fatigue life requirements.


The client's innovative vessel is the first ship-shaped, dynamically positioned floating production unit (FPU) used in the Gulf of Mexico. Rather than build new, the client chose to convert a roll-on/roll-off ferry vessel. During the design process, the client encountered difficulty achieving sufficient fatigue life in the side-mounted turret system structure. The client needed a post-weld treatment for high cycle fatigue life improvement and chose Applied Ultrasonics' UIT solution because it provides control and efficiency far surpassing all alternative methods such as post weld heat treatment.


Applied Ultrasonics' Ultrasonics Division, working closely with the client and the shipyard throughout the design and fabrication process, improved the welds of the lantern frame and external moonpool structure. The speed, efficiency, and consistency of Ultrasonic Impact Technology (UIT) ensured that the client maintained its schedule in the shipyard. Following application of UIT ultrasonic technology to key areas, the client used the Lloyd’s Register improvement factor on life to exceed the fatigue design criteria. Upon commissioning, the vessel began production in the Gulf of Mexico and is now a key vessel in the client's fast response system for well containment. Applied Ultrasonics' Ultrasonics Division provided the requisite structural strength, integrity, and fatigue life for both roles.




Applied Ultrasonics has repeatedly extended the life of infrastructure assets, from bridges to mining business equipment to ship building technology offshore oil and gas drilling rigs.  Applied Ultrasonic can provide service onsite to maximize cost effectiveness for the customer. To learn how Applied Ultrasonic can help your company, please contact us.

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