Influence of mechanical layout of inerter systems on seismic mitigation of storage tanks

Investigations concerning impact of the mechanical layout of two typical inerter systems on mitigation of seismic response of a base-isolated storage tank are reported. To this end, parameter assessment was first performed to determine impact of the mechanical layout of inerter systems on the sloshing height, isolation displacement, base shear force, and overturning base moment of the storage tank. Conditions favorable for the design suitable of each inerter system were identified based on results of parametric analysis performed as per design guidelines. In addition, the study proposes a demand-oriented optimum design method for determining design parameters of the bearing and inerter systems to meet target performance levels of the storage tank. The proposed method facilitates design of inerter systems with different mechanical layouts. Under the same target level of vibration mitigation in storage tanks, two typical inerter systems have been designed to further explore the impact of inerter-system mechanical layouts. Finally, frequency-domain and time-history analyses were performed on numerical cases of storage tanks with above-designed inerter systems. Analyses results demonstrate that a suitable inerter-system mechanical layout can be selected in accordance with design guidelines prior to design optimization of an inerter system. Using the proposed optimum-design method, inerter systems could be designed to realize target performance levels of the storage tank. In addition, the impact of the inerter-system mechanical layout on mitigation of seismic response of a base-isolated storage tank has been appropriately considered in the proposed demand-oriented optimum-design method.