Dynamic response assessment of an offshore jacket platform with semi-active fuzzy-based controller: A case study. (15th October 2021)

• Record Type: Journal Article
• Authors: Ghadimi, Behnam; Taghikhany, Touraj
• Is Part Of: Ocean engineering. Volume 238(2021)
• Publication Date: 2021-10-15
• Subjects: Offshore jacket platform -- Environmental loading -- Seismic loading -- Semi-active control -- Inverse dynamic model -- Dynamic time history analysis; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109747
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: The present study investigates the dynamic responses of offshore jacket platforms using a passive and semi-active tuned mass damper (TMD, SATMD), where the control action is achieved by a fuzzy logic controller (FLC) under environmental (i.e., wind, water waves, sea currents) and seismic loadings. Since the studied structure failed to meet recent codes requirements adequately, the suppressing effect of a SATMD is considered as a way to retrofit structural performances under hydrodynamic loadings. After extraction of the dynamic properties of the jacket-type structure, simulations of an installation system with and without a TMD have been performed, and the effectiveness of TMD is quantified. In order to exploit the potential of the structure to overcome all types of excitations, the SATMD comes complete with a fuzzy-algorithm-controller, acknowledging that the use of a passive TMD is only a preliminary attempt to reduce the structure's dynamic responses. Comparison of the results indicates a significant response value reduction in acceleration, base shear, overturning moment, velocity and lateral displacement of a case study of steel jacket platforms. Highlights: Assessment of an Offshore Jacket Platform in Accordance with the Site Characteristics of the Persian Gulf. Comparing Value Reduction in Structural Responses Due to Environmental Loading and the Strongest Local Earthquake. Using Time Domain Extreme Random Wave Analysis to Derive Water Surface Profiles from JONSWAP and Pierson-Moskowitz Spectra. Proper placement of TMD, MR Dampers and Sensors to Design Semi-Active Collocated-Control System. Stability of the Closed-Loop Fuzzy Control System through Passivity Principle, Nyquist and BODE Plots.