STRUCTURAL ANALYSIS OF NODE CUT-OUTS IN A SEMI-SUBMERSIBLE OFFSHORE PLATFORM
Paper i proceeding, 2016

The connection between column and deck-box on a semi submersible platform is often subjected to high stress concentrations that can be governing for the structural strength. One common design used to withstand the high stresses is a cast integral in high tensile material, which is both heavy and expensive to manufacture, which is why an alternative cut-out design is investigated. This study presents an analysis of a node connection with regard to yield stresses, buckling, fatigue damage, weight and cost in order to propose an alternative cut-out design using the same criteria. The cast integral, which is analysed as a reference case and used for comparison of designs, is of a typical design used today. A parametric study shows that the use of a cut-out design may be advantageous in the centre bulkhead connection between the column and the deck-box. The adjacent geometry is of simple character and the cut-out does not affect the overall structural design. The cut-out is found to be a feasible alternative to the cast integral, with yield stresses and fatigue damage in the same range. Further refinements of the cut-out design could, however, decrease both yield stresses and fatigue damage. A suggested cut-out solution leads to a decrease of 4.5% in weight for a reference structure. For the same reference structure the production cost is estimated to decrease by 9%, hence, the cut-out design is recommended for the centre bulkhead connection.

semi-submersible

stress

stress redistribution

cast integral

plates

stress concentration

cut-out

Författare

Jonas Ringsberg

Chalmers, Tillämpad mekanik, Material- och beräkningsmekanik

Chalmers, Tillämpad mekanik

Chalmers, Sjöfart och marin teknik, Marin teknik

Daniel Karlsson

Chalmers, Sjöfart och marin teknik, Marin teknik

Mårten Forser

Chalmers, Sjöfart och marin teknik

Chalmers, Sjöfart och marin teknik, Marin teknik

PROCEEDINGS OF THE ASME 35TH INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING , 2016

Vol. VOL 3

Drivkrafter

Hållbar utveckling

Fundament

Grundläggande vetenskaper

Ämneskategorier

Farkostteknik

ISBN

978-0-7918-4994-1