Feasibility study of the physical implementation of rate-independent linear damping for the protection of low-frequency structures

Damage to nonstructural components or excessive displacements in low-frequency structures caused by recent major earthquakes, such as the 2011 Great East Japan Earthquake, highlighted the need to protect these structures against earthquake-induced damage. Rate-independent linear damping (RILD) has been found to be a viable option for reducing the excessive displacement of low-frequency structures because its control force is larger in the low-frequency region than that of conventional damping elements. Most of the studies on RILD have focused on theoretical and mathematical aspects rather than their practical application. The main objective of this study was to examine the feasibility of the physical implementation of RILD for the protection of low-frequency structures. In this study, a passive causal RILD (CRILD) device comprising a Maxwell element and a negative stiffness element was considered to mechanically realize RILD. Numerical analysis and real-time hybrid simulation (RTHS) on a single-degree-of-freedom (SDOF) system incorporated with the proposed device were performed to identify the challenges in the physical implementation of a passive CRILD device. The results confirmed that CRILD can achieve a similar control effect of low-frequency structures to the ideal RILD and can reduce structural dynamic responses more effectively than the commonly used linear viscous damping (LVD) model.