NON-LINEAR FINITE ELEMENT ANALYSIS OF DECK, BOTTOM AND INNER BOTTOM PANELS IN FPSO VESSEL

Öz

Floating production, storage and offloading systems (FPSOs) are widely used to develop offshore oil and gas fields. FPSOs structures shall be evaluated in order to satisfy the specifications of both in-service and pre-service loading conditions. The key aspects of the structural assessment of FPSOs are the buckling and ultimate strength behaviour of plate panels, stiffened panels and hull girders. The focus of this paper is to address the buckling and ultimate strength criteria for FPSO hull structures. Buckling strength assessment of three panels in FPSO vessel is being carried out using the non-linear finite element code ADVANCE/ABAQUS, where the analyses involve both material inelastic effects and non-linear geometric effects. The capacities of the bottom panels are estimated under simultaneously acting lateral pressure and axial compression. The upper deck is only subjected to axial compression. The three panels are located in the upper deck, the inner bottom and the bottom shell. The capacities of the bottom panels are predicted under simultaneously acting lateral pressure (0.249 MPa for inner bottom and 0.146 MPa for the bottom) and axial compression. For both the bottom and the inner bottom panel the pressure acts from the ballast tank and outward. The upper deck is only subjected to axial compression. The Ultimate Limit State (ULS) capacities have been estimated to 260 MPa for the upper deck, 205 MPa for the inner bottom and 250 MPa for the bottom shell.

Anahtar Kelimeler

• non-linear finite element
• FPSO vessel
• axial compression
• lateral pressure
• buckling capacity

Kaynakça

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