Effect of shape memory alloy-magnetorheological fluid-based structural control system on the marine structure using nonlinear time-history analysis

•The experimental tests of shape memory(SMA) alloy and magnetorheological fluid(MRF) damper are conducted.•The numerical model of SMA and MRF damper are modeled in OpenSees and validated.•The numerical model of smart SMA-MRF based bracing system is performed.•Dynamic responses of the marine structures with and without bracing systems are investigated and compared each other.•Remarkable enhancements of the structure are found in result of the smart bracing system. Marine structures, as key elements in the global energy network, constantly are subjected to harsh environmental loading conditions. Therefore, reliable yet efficient structural control mechanisms are required to ensure their safe functionality and structural stability. In the present work, a novel hybrid structural control element for marine structures has been designed in which the superelasticity effect of shape memory alloy (SMA) and damping controllability of magnetorheological fluid (MRF), as smart materials, have been combined. The novel system does not require huge external energy for activation and in addition, the system has the ability to be tuned for variable loading conditions. To show the functionality of the proposed control system, the performance of a simplified marine structure equipped with the present novel control system is evaluated by simulating the response of a sample structure under three scaled ground motions, namely, Christchurch, Imperial Valley, Parkfield. The results are compared to structures with the SMA-based system and structures with the MRF-based control system. It is observed that the present hybrid SMA-MRF control system significantly improves the performance of marine structures under seismic loadings.