Damping systems that are effective over a wide range of displacement amplitudes using metallic yielding component and viscoelastic damper in series

Abstract

A damper system that absorbs energy over a wide range of displacement amplitudes during building vibration was proposed. This system uses a serial connection of a metallic yielding component and viscoelastic damper with a displacement limit mechanism. Three types of the system were developed and tested: a diagonal bracing type, inverted V bracing type, and wall type. The test results showed that all these systems have damping ratios higher than 8% at small vibration amplitudes on the order of 0.1 mm. For a large vibration, a displacement limit mechanism with two pins limited the displacement of the viscoelastic damper as designed. Analytical simulations established that the system reduced the acceleration and the story drift to 60-70% and 80%, respectively, during a small earthquake compared with a conventional metallic yielding damper system. Furthermore, it showed an equivalent control performance during a severe earthquake. The damper system requires that a clearance be maintained for the displacement limit mechanism. However, this may be lost through construction error, residual displacement after an earthquake, and temperature effects. The changes in the clearance due to these effects were discussed.Corrugated steel plates have a high shear buckling strength; therefore, they need little stiffening. Multiple VE dampers were installed between the shear panel and beam of the building [26].The 'wall type' was applied in a 21-story steel hotel and office building complex in Hiroshima. Dynamic loading test for VE damperA full-scale VE damper was tested during small vibrations, which are expected to affect human comfort. Figure 11 shows the test specimen. The VE material is the same as that used in the bracing types. This was a double-layered shear-type damper in which each layer consisted of 2.0-mm-thick press-vulcanized rubber adhered to steel plates. In the center of the VE damper, one stopper pin penetrated the damping layers. The diameters of the pin and the hole in the steel plates were 56 and 60 mm, respectively. It should be noted that the pin was fixed to the inner plate, whereas the pins of the bracing types were not fixed to any plates. In this system, when the displacement of the VE damper reaches 2 mm (0-p), the pin touches the outer steel plates and begins to restrict the displacement. This specimen was tested using a 50-kN dynamic loading test machine. The base of the inner plates was fixed to the reaction base of the machine, and the outer plates on the actuator head of the machine were guided by a linear motion rail. Two specimens were tested. Figure 10. Test results during quasi-static loading whose amplitude was gradually increased until story drift reached 23 mm. Figure 11. Test specimen of viscoelastic (VE) damper of 'wall type'.

Recent research and development of structural control in Japan

“…Combined uses are categorized as (i) active, semi‐active, and passive control; (ii) passive control for small vibration and passive control for large vibration; (iii) structural control and base isolation; and (iv) passive control using complex dampers for small and large vibration. A complex damper is defined as a device with multiple functions, such as the integration of a visco‐elastic damper and a hysteresis damper …”

Experimental beyond design and residual performances of full‐scale viscoelastic dampers and their empirical modeling

“…For purposes other than seismic protection, VE dampers were used for attenuating excessive floor vibration due to human activities . To make VE dampers absorb energy over a wide range of displacement amplitudes without suffering damage, Yamamoto and Sone developed and tested a serial connection of a metallic yielding component and a VE damper.…”

Concept and performance testing of a high‐capacity oil damper comprising multiple damper units

“…The authors have been actively engaged in the application and development [1] of supplemental dampers and have often encountered cases that required high-capacity dampers that are presently not available. The authors have been actively engaged in the application and development [1] of supplemental dampers and have often encountered cases that required high-capacity dampers that are presently not available.…”

“…The use of supplemental dampers to enhance the seismic safety of structures has become popular in Japan in recent times. The authors have been actively engaged in the application and development [1] of supplemental dampers and have often encountered cases that required high-capacity dampers that are presently not available. The scale of building structures has been on the increase, and this has necessitated high-performance structural control.…”