Improved Method of Strength Analysis of Self-Elevating Mobile Offshore Drilling Units Under Wind and Wave Loads

Methods and software for strength analysis of jacking systems of self-elevating mobile offshore drilling units (MODU) used in MODU design by Central Design Bureau (CDB) CORALL (calculation meth-ods Lit-1, Leg-1 and Leg-2) are reviewed.
The focus is on Method Leg-2 (Corall) that uses modern means for self-elevating MODU calculation. It is based on the finite element analysis (FEA) used not only for stress-strain state analysis of the legs but also for determination of hydrodynamic loads. This method is characterized by the finite-element model of both the legs and the hull, i. e. the model of self-elevating MODU as a whole. All methods are universal and suitable for the self-elevating MODU intended for both deep and shallow waters, both for gridwork and cylindrical legs. Conclusions are made for advanced application of innovative methods mentioned above and their hypothetical implementation in the RS rules.

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UDC:  629.124: 622.242: 539.4
Author(s):  Berkhin I.M., Litonov O.E.
Pages:  141 -150