Response of base isolated systems equipped with tuned mass dampers to random excitations

Abstract

A new structural system conceived to control Base Isolated System vibrations under random excitations is analyzed. The new system combines the Tuned Mass Damping strategy with the Isolation concept in order to obtain a new system which principally attenuates the effects of the seismic excitation components with frequencies close to the fundamental natural vibration one. The Random response of equivalent linear Base Isolated Systems controlled by Tuned Mass Dampers subject to horizontal random excitations is analyzed. Considering the superstructure motion described by its first modal contribution, a three‐degree‐of‐freedom linear model subject to stationary Gaussian excitations, modelled by the modified Kanai‐Tajimi power density spectrum, was used in this analysis. The standard deviation response ratio of the new system respect to the one of the base isolated system was evaluated based on a wide range of parameters. Optimal parameters which minimize structural response were also obtained.

Optimum design for more effective tuned mass damper system and its application to base-isolated buildings

“…In this regard, it is expected to effectively prevent base‐isolated high‐rise buildings from the aforementioned situation. Some researchers proposed and studied the hybrid control strategy of combining traditional TMDs with base‐isolation systems and demonstrated the effectiveness of TMDs . However, a traditional TMD would need a large stroke to diminish the large responses of the primary structure in the event of resonance, and thus, a large clearance is needed to accommodate the large stroke.…”

Optimal tuning and assessment of inertial dampers with grounded inerter for vibration control of seismically excited base-isolated systems

“…To this end, a number of researchers [11][12][13][14][15][16] explored the potential of the tuned mass-damper (TMD), i.e., the most widely used passive linear inertial damper in vibration control applications [17], to mitigate lateral drifts in BISs. The latter strategy, involves attaching a free-to-vibrate mass to the isolation layer of the BIS via a viscoelastic link (i.e., linear spring/stiffener in parallel with a linear viscous damper) tuned/designed such that significant kinetic energy is transferred from the BISs to the attached (secondary) mass and eventually dissipated by the damper.…”

Optimal structural control in the frequency domain: Control in norm H2 and H∞

“…Consider the shear-type 10 story frame isolated system represented in figure 4 and equipped with an hybrid mass damper 1995). In the hypothesis of equivalent linear behavior the motion equations in the state space are given by: Furthermore, the system is described by the following matrices: M , C and K respectively being the mass, the damping and stiffness matrices; b, and b, the vectors that influence the seismic excitation and the control force; 0 and I the null and the identity matrices of opportune dimensions.…”