NONLINEAR ANALYSIS OF OFFSHORE STRUCTURES UNDER WAVE LOADINGS

Abdel Raheem, Shehata E.; Abdel Aal, Elsayed M. A.; Abdel Shafy, Aly G. A.; Abdel Seed, Fayez K.

doi:10.21608/jesaun.2012.114403

NONLINEAR ANALYSIS OF OFFSHORE STRUCTURES UNDER WAVE LOADINGS

Document Type : Research Paper

Authors

¹ Assoc. Prof. of Earthquake, Structural and Geotechnical Engineering, Taibah University, KSA. On leave; Faculty of Engineering, Assiut University

² Senior Off-Shore Structural Engineer, Egypt Gas Company.

³ Prof. of Structural Engineering, Civil Engineering, Faculty of Engineering, Assiut University.

10.21608/jesaun.2012.114403

Abstract

The structural design requirements of an offshore platform subjected wave induced forces and moments in the jacket can play a major role in the design of the offshore structures. For an economic and reliable design; good estimation of wave loadings are essential. A nonlinear response analysis of a fixed offshore platform under wave loading is presented, the structure is discretized using the finite element method, wave force is determined according to linearized Morison equation. Hydrodynamic loading on horizontal and vertical tubular members and the dynamic response of fixed offshore structure together with the distribution of displacement, axial force and bending moment along the leg are investigated for regular and extreme conditions, where the structure should keep production capability in conditions of the one year return period wave and must be able to survive the 100 year return period storm conditions. The result of the study shows that the nonlinear response investigation is quite crucial for safe design and operation of offshore platform.

Keywords