Abstract

Abstract: Tubular X-joints are used extensively in leg assemblies of jack-up platforms and jacket structures. As a result of Hurricanes Katrina and Rita in 2005, existing platforms will be required to resist significantly higher loads with associated demand on the critical tubular members and joints. For older platforms, there is a corresponding need to retrofit crucial joints to ensure adequate fatigue capacity.

This presentation will highlight results of a comprehensive experimental and numerical investigation on the effect of strengthening the chord with high strength grout (with compressive strength of 210 MPa) on the reduction of hot spot stresses and corresponding enhancement in static strength of tubular X-joints. The numerical results are found to be in close agreement with those obtained from the four experimental tests, with a reduction of 30% for the critical hot spot stress for the grout-reinforced joint. The strength enhancement of the grouted joint was up to 2.6 times that of the as-welded simple joint.

About the speaker: Professor Yoo Sang CHOO is currently President of The Institute of Marine Engineering Science & Technology (IMarEST). He was mentored by Professor Michael Horne in University of Manchester. He has served in many scientific or technical committees of international organizations and conferences, and hosted as Chairman or Co-Chairman for some of these conferences. He served as President of Singapore Structural Steel Society from 1992 to 1994. He is member of Editorial Board for three international journals, and member of International Institute of Welding Sub-commission XV-E: Tubular Structures and member of Technical Committee III .1: Ultimate Strength in International Ships and Offshore Structures Congress. Professor Choo has received a number of international and national recognitions, including ISOPE Awards, Stanley Gray Award, IES Prestigious Engineering Achievement Award, James Watt Medal and Stanley Gray Medal. Professor Choo was conferred the Honorary Fellowship of Singapore Structural Steel Society in 2004 in recognition of his technical expertise and contributions in Offshore and Structural Engineering. He has served as technical consultant in major offshore projects, and participates in international joint industry projects.