Advanced Vibration Control of the Resalat Offshore Jacket Platform Under Seismic Excitations: A Compara-tive Study of Active and Semi-Active Dampers

In this research is to study the vibration control of the Resalat offshore jacket platform in the Persian Gulf due to benchmark earthquakes, such as El Centro, Hachinohe, Kobe, and Northridge. In this respect, an offshore platform is controlled using active and semi-active damping systems. For the active control system, a linear actuator with the New Algorithm (NA) control algorithm was employed, while for the semi-active control, a magnetorheologi-cal (MR) damper was used in both passive-off and passive-on modes. The design of the MR damper was based on the maximum force determined by the NA algorithm, ensuring its ca-pacity met the required damping force. Simulation of the structural model using MATLAB with Simulink was conducted, was analyzed the performance of the offshore platform under the various earthquake scenarios. The results show that the active control system significantly reduces the maximum displacement and has performed better than the semi-active MR damper in passive-off and passive-on modes. Maximum displacements under the benchmark earthquakes for uncontrolled and active systems were reduced from ۰.۴۹ (m) (uncontrolled) to ۰.۰۱۴ (m) (active) on average. However, in terms of maximum acceleration, the semi-active system was outperformed by the active system in certain cases, indicating a trade-off between displacement reduction and acceleration control. These findings demonstrate the ef-fectiveness of both active and semi-active control systems in mitigating vibrations under seismic conditions, with potential implications for the design and optimization of offshore platforms in earthquake-prone regions.

کلیدواژه ها:

Offshore jacket platform ، NA algorithm ، Active damper ، MR damper