Bowstring-type inerter negative stiffness damper for vibration control of slender towers

Abstract

The difficulty of practical installation restrains the application of tuned damping devices in the high-performance vibration control of slender towers. In order to address this issue, a novel Bowstring-type Inerter Negative Stiffness Damper (BINSD) is proposed. The BINSD is composed of an inerter-negative-stiffness-dashpot system connected between the tower and a mass block (or a massless node) located on a vertical prestressed cable like a bowstring. In order to determine the multiple optimal parameters of the proposed BINSD, analytical parametric optimizations are investigated for the following three aspects. Firstly, the optimal tuning frequency and damping ratios are obtained via an analytical approach considering H∞ and H2 norms. Secondly, the optimal negative stiffness is determined by balancing the static and dynamic performances, particularly for practical excitations with mixed static and dynamic components (such as wind). Thirdly, the optimal installation height is analytically derived to fulfil a least negative stiffness criterion, which leads to an economic realization in practice. Finally, the effectiveness of the presented BINSD and corresponding optimal design approaches is numerically validated by the wind- and seismic- induced vibration control cases of a wind turbine tower. The proposed optimal design approaches lead to a high-performance, economic, and feasible design of BINSD.