Improvement Analysis of Response Between Jacket Platforms and Sea Waves using the Vibration Dampers

Subject Areas : vibration and control

Latif Pendarian ¹ , Alireza Fiouz ^{2 *} , Abbas Gasemi ³

1 - Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
2 - Department of Civil Engineering, Persian Gulf University, Bushehr, Iran
3 - Department of Civil Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran

Received: 2022-06-27 Accepted : 2022-10-23 Published : 2023-06-01

Keywords: initial conditions, inertial forces, Liquid damper with rectangular tank, Eulerian, fluid solution field, Navier-Stokes equations,

Abstract :

Offshore fixed metal platforms have unique characteristics in specific location such as shallow waters, and oil platform may be physically connected to seabed. Offshore platforms in the sea are affected by complex and destructive forces caused by wind, waves, marine currents, earthquakes and even large displacement vortex forces. The purpose of refurbishing metal fixed platforms is to somehow equalize the capacity of the structure with its seismic requirements. In some cases, they increase the capacity of the structure to meet seismic requirements. In this research, dynamic vibration absorbers or dampers, such as passive dampers, fluid system adjusted for damping vibrations and reduced structural response against wave and earthquake hydrodynamic loads will be used as an efficient control method. The purpose of this research is to improve the performance of the liquid platform vibration damping of the metal platform. The results show that equipping offshore platforms with liquid damping systems has a good performance on the safety and dynamic behaviour of the platforms and has a significant effect on the displacement response and acceleration of the platform under study at its highest deck level. Also, as the water depth in the tank increases, the damping value for the rectangular and cylindrical tanks decreases and the rectangular tank creates more control and damping force than the cylindrical tank.

References:

• Dean, E. T. R., Offshore Geotechnical Engineering, 1st Edition, Thomas Telford Limited, 2010.


• Wilson, J. F., Dynamics of Offshore Structures, John Wiley & Sons, 2003.


• Abdel-Rohman, M. 1996. Structural Control of Steel Jacket Platform. Structural Engineering and Mechanics., 4: 25–38.


• McCormick, M. E., Ocean Engineering Mechanics, Cambridge University Press, 2010.


• Abramowitz, M., Stegun, I. A., Handbook of Mathematical Functions, New York- Dover Publications, 1965.


• Mogridge, G. R., Jamieson, W. W., Wave Forces on Large Circular Cylinders: A Design Method, Hydraulics Laboratory, National Research Council of Canada, Report MH-111, 1976.


• Stansberg, C. T., Baarholm, R., Fokk, T., Gudmestad, O. T., and Haver, S., Wave Amplification and Possible Deck Impact on Gravity-Based Structure in Probability Extreme Crest Heights, 23rd International Conference on Offshore Mechanics and Arctic Engineering, 2004.


• Glagovsky, V. B., Estimation of Seismic Stability of Gravity Base Substructure for Fixed Offshore Platform, Vedeneev Research Instititute, St. Petersburg, Russia, 2012.


• Vincenzo, G., Roger, G. 1999. Adaptive Control of Flow-Induced Oscillation Including Vortex Effects. International Journal of Non-Linear Mechanics., 34: 853–868.


• Ou, J.P., Xiao, Y.Q., Duan, Z.D., Zou, X.Y., Wu, B., Wei, J.S. 2000. Ice-induced Vibration Control of JZ20-2MUQ Platform Structure with Viscoelastic Energy Dissipaters. The Ocean Engineering., 18(3): 9–14.


• Ding, J.H. 2001. Theoretical and Experimental Study on Structural Vibration Repressed System Using Viscous Fluid Dampers. Ph.D. dissertation, Harbin Institute of Technology. [in Chinese].


• Patil, K.C., Jangid, R.S. 2005. Passive Control of Offshore Jacket Platforms. Ocean Engineering., 32: 1933–1949.