Neuro fuzzy logic control of magnetorheological elastomer isolation system for vibration mitigation of offshore jacket platforms

Abstract

Undesirable vibrations in offshore platforms due to environmental loadings reduce platform productivity and service life. This study proposes a magnetorheological elastomer (MRE) based isolation system to control the jacket platform dynamic responses under multiple loadings, namely the earthquakes and irregular waves. The dynamic model of jacket platform with MRE system is established, and a semi-active neutron-fuzzy controller is proposed for real time vibration mitigation. To evaluate the MRE-based isolation system effects on the vibration suppression of the jacket platforms under multiple loadings, a JZ20-2MUQ platform located in Bohai Sea of China is selected as a case study, and a comprehensive numerical study has been conducted. The results demonstrate that the MRE-based isolation system can effectively attenuate the dynamic responses of offshore platform. The effectiveness of the proposed MRE system is also evaluated by comparing a previous magnetorheological fluid damping system, which presents the superiority of MRE system for suppressing multiple-direction loadings.