Vibration control of offshore jacket platforms through shape memory alloy pounding tuned mass damper (SMA-PTMD)

The production of intelligent materials in the design of vibration control devices have made significant progress in the past two decades. Since the shape memory alloy (SMA) is a superelastic intelligent material highly capable of dissipating energy, use has been made in this research of the SMA pounding tuned mass damper (SMA-PTMD) to control the wave-induced vibrations of the offshore jacket platforms. The SMA-PTMD dynamic vibration absorber (DVA) is a combination of SMA-TMD and PTMD connect the mass to the deck through a piston-based SMA dissipation device composed of varying-geometry SMA bars and gaps. Here, the vibration equations have been developed by simulating the platform and the DVA as a multi-degree of freedom system and solved by the direct integration method. To define the SMAs' hysteretic behavior, its idealized constitutive model has been implemented and the geometry of the SMA bars has been adjusted using the ideal gas molecular movement optimization algorithm. The time history responses have indicated significant reductions in the maximums and RMS of the deck displacements of the optimized SMA-PTMD-installed jackets vibrated under the action of irregular waves. Results have also shown high tuning and robustness of the SMA-PTMD under broadband frequency excitations and off-tuning conditions.