The authors have proposed the tuned viscous mass damper system based on the fixed points theory, and have proved the validity of the theory and the analysis method through the vibration tests of the small scale test specimen. The testing program revealed that an increase in equivalent inertial mass of viscous mass damper and increase in input resulted in an excessive stresses in the supporting member, damper body and the primary structure connected to the damper. In this paper, authors built the rotation slipping mechanism into the main body of the full-scale tuned viscous mass damper with the spring member of 18,200kN/m and the equivalent inertial mass of 1,350ton, and tested the tuned viscous mass damper with the force restriction mechanism. Analysis parameters of the tuned viscous mass damper with the force restriction mechanism were evaluated accurately and the test results corresponded well with the analytical results. From the analysis results for a 1-story structure, it is shown that this restriction mechanism can effectively reduce the damper maximum force and the maximum response displacement is almost the same as the result obtained by a restriction-free damper.

The authors have proposed the single-tuning viscous mass damper system based on fixed points theory. Vibration control effects of singletuning type system are very sensitive to changes of parameters such as the natural frequency of the controlled object and the damping coefficient of the absorber itself. In this paper, response control method using multi-tuning type system with diversified natural frequencies is proposed. It is shown that the multi-tuning type system proposed herein is considerably effective in improving the reduction efficiency of the response magnification factor than single-tuning type system.

This paper shows application of viscous mass damper with restriction mechanism to base-isolated structures, and its effectiveness.Damper force restriction mechanism was modeled by complex stiffness model and it shows the response characteristic of this system based on equivalent linearization method. The effectiveness of this system was examined by non-linear time history response analysis using seismic waves. These results confirmed that it is possible to apply large added mass to base-isolated structures, and that large displacement reduction effect was achieved by using damper force restriction mechanism. At this time, damper force restriction mechanism clearly showed that damping force can be controlled.

In this paper, we propose installing a buffer spring into a base-isolated system incorporated with a viscous mass damper as a method to reduce excessive acceleration induced by the secondary mass. We derived transfer functions of a two-degree-of freedom model on the basis of equivalent linearization method using complex stiffness model and the effectiveness of this system was examined by non-linear time history response analysis for real buildings. These results confirmed that the buffer spring as well as the damper force restriction is effective in reduction of accelerations and damper forces without deterioration in displacement reduction effect brought by the secondary mass.

The authors have conducted full-scale dynamic tests of the largest forcerestricted tuned viscous mass damper (FRTVMD), and analyses of a single-degree-of-freedom structure incorporated with the FRTVMD. A comparison verified the validity of the linearization method for a nonlinear viscous element in the FRTVMD.