Perpustakaan Digital ITB

During operation, the offshore pipeline is continuously subjected to hydrodynamic loading induced by ocean currents, which may generate vortex-induced vibration (VIV). The resulting cyclic loading is transmitted to the support system through the pipe clamp, which making the clamp one of the critical components susceptible to fatigue failure. This study aims to analyse the fatigue behaviour of an RTP pipe clamp subjected to hydrodynamic loading using a one-way Fluid–Structure Interaction (FSI) approach with global multiscale structural analysis. Computational Fluid Dynamics (CFD) simulations were performed on two representative pipeline sections located at the Mean Sea Level (MSL) and the seabed using with the SST k–? turbulence model. The resulting lift forces were interpolated along the pipeline and transferred to a global beam model through a one-way FSI framework. Reaction forces at each pipe clamp were extracted from the global structural analysis and subsequently applied to a detailed local structural model of the pipe clamp. The fatigue life was then evaluated using the theoretical approach and verified using the ANSYS Fatigue Tool. The CFD validation demonstrated that the developed model successfully conducts the principal vortex shedding characteristics, with ????????,???????????????? of 0.861 and a ????????,???????????? of 0.447. The global structural analysis identified Clamp 3 as the most critical support location, with a maximum reaction force of 191.55 N. The maximum von Mises of the clamp is 1.8342 MPa, which is significantly lower than the corrected endurance limit of ASTM A36 steel (104.41 MPa). The fatigue assessment predicted a fatigue life of 6.25 × 1015 cycles with a cumulative fatigue damage of 6.30 × 10??, satisfying the DNV-RP-F204 acceptance criterion for a 20-year design life. Therefore, the pipe clamp in this research is considered safe against fatigue failure under the specified offshore operating conditions.