Control of Offshore Jacket Platform Vibrations under Dynamic Loads of Sea Waves Using Self-Powered Semi-Active Mass Damper

Offshore jacket platforms play an important role in the oil and energy industry, so controlling the vibrations of these structures and increasing their useful life is of great importance. In this study, the dynamic response of the offshore jacket platform under the effect of wave load with a return period of 100 years has been investigated. To reduce the dynamic response of the oil rig deck, a self-powered semi-active mass damper (SP-SATMD) was used and its mass ratio was set at 3% by default. The magneto-rheological damper (MR) energy in a semi-active tuned mass damper is supplied by the vibration of the tuned mass damper through an energy extraction system. This system includes DC direct current generator, rack and pinion. The rack and pinion convert the linear motion of the mass damper into an angular motion and apply it to a DC generator to generate electrical energy. The energy extraction system itself can also act as an electromagnetic damper (EM) and a proportional control algorithm in determining the damping of the magneto-rheological damper. The results show that the maximum displacement and acceleration of the offshore jacket platform deck in its semi-active control mode decreased by 15 and 16.24%, respectively, compared to the uncontrolled mode.