Experimental verification of seismic vibration control using a semi-active friction tuned mass damper

A tuned mass damper (TMD) system consists of an added mass with properly functioning spring and damping elements for providing frequency-dependent damping in a primary structure. The advantage of a friction-type TMD, that is, a nonlinear TMD, is its energy dissipation via a friction mechanism. In contrast, the disadvantages of a passive friction TMD (PF-TMD) are its fixed and predetermined slip load and loss of tuning and energy dissipation capabilities when it is in a stick state. A semi-active friction TMD (SAF-TMD) is used to overcome these disadvantages. The SAF-TMD can adjust its slip force in response to structure motion. To verify its feasibility, a prototype SAF-TMD was fabricated and tested dynamically using a shaking table test. A nonsticking friction control law was used to keep the SAF-TMD activated and in a slip state in earthquakes at varying intensities. The shaking table test results demonstrated that: (i) the experimental results are consistent with the theoretical results; (ii) the SAF-TMD is more effective than the PF-TMD given a similar peak TMD stroke; and (iii) the SAF-TMD can also prevent a residual TMD stroke in a PF-TMD system. Copyright (C) 2011 John Wiley & Sons, Ltd.