Codification of tubular joints design practice

Tubular jacket structures comprise tubular members connected at their ends to form tubular joints. Large research programmes over the past two decades have generated a significant amount of test data and information on all aspects of static strength, stress analysis and fatigue life evaluation. These data have been used by various design codes, such as API RP2A and the UK Guidance Notes, to develop design recommendations. However, while the recommendations in various design documents are derived essentially from the same database, a significant number of differences exist in the recommendations, leading to designs which are appreciably different, depending on the adopted design code. This paper concentrates on static strength and addresses the background to these differences and their implications to design. Areas of concern are cited and an approach to rationalization is developed, leading to the specification of future design development and research activities. The use of suitable forums for rationalization, such as the established Tubular Joints Group and the pending Offshore Eurocode, is described and discussed. Whist this paper addresses static strength, the need to rationalize design practices in respect of stress analysis and fatigue life evaluation equally applies