Numerical investigation of a smart control system for enhancing seismic performance in the horizontal and vertical vibrations of a cabinet

As the seismic performance requirements for nuclear power plants have become more stringent, interest in the seismic performance of nuclear power plant equipment has also increased. Equipment damage is categorized into structural and functional damage, with functional damage caused by high acceleration at lower seismic intensities than structural damage. To ensure the safety of nuclear equipment, damage from vertical seismic forces must be considered along with horizontal forces. This study proposes a smart vibration control system to effectively enhance the seismic performance of nuclear cabinets in both horizontal and vertical directions. Base isolation was employed for horizontal vibration control, while vertical springs and magnetorheological (MR) dampers were installed for vertical vibration control. A two-dimensional model was designed to conduct numerical analysis, simulating the dynamic behavior of the vibration control devices in detail. The results confirm that the proposed smart control system effectively improves the seismic performance of the cabinet in both directions and mitigates the rocking motion of slender structures.