1. SEISMIC CONTROL OF BUILDINGS USING APPARENT MASS DAMPERS WITH ROTATIONAL AMPLIFYING MECHANISMS Assistant Prof. Ruifu Zhang Research Institute of Structural Engineering and Disaster Reduction Tongji University, China

2. BACKGROUND Missing 2-node mechanical element and ideas of a 2-node apparent mass device

3. Consider a simple SDOF system

4. Spring Element Damping Element 2-nodes mechanical elements

5. A missing 2-nodes mechanical element Chen, Michael ZQ, et al. "The missing mechanical circuit element." Circuits and Systems Magazine, IEEE 9.1 (2009): 10-26. O Inertial Reference Frame

6. 2-nodes Apparent Mass Devices Inerter (Smith, 2000) Dynamic Mass (Furuhashi and Ishimaru, 2004)

7. Inertia Pump using Fluid Mass (Kawamata, 1973)

8. 2-nodes apparent mass devices Hydraulic Inerter (Wang F-C. et al. 2010) Leveraged-Pendulum System (Yamamoto, 1975) Rack and Pinion System (Okumura, 2000)

9. Building Dampers using Apparent Mass Apparent Mass Damper using Ball-Screw Mechanism (Aragaki et al. 1999)

10. Building Dampers using Apparent Mass Rotary Damping Tube (RDT)

11. The most viable and promising 2-nodes apparent mass device Ball Screw Silicone Oil Cylindrical Flywheel

12. Photo of the full scale real-life damper Apparent mass = 5400 t

13. Apparent mass device for seismic isolation

14. Full-Scale Real-Life Damper Apparent Mass: 1250 t

15. RESPONSE CONTROL USING APPARENT MASS

16. Vibration Insulator The 2-nodes apparent mass device cuts off the harmonic excitation of a specific frequency (Okumura 2000) if, X = 0

17. Seismic Control Hwang et al. (2007) studied seismic control of building structures using an inerter-like or dynamic mass-like device combined with toggle amplifier. Seismic retrofit of existing high-rise building using an inerter-like device dynamic screw. (Matsui et al. 2012)

18. TMD-like system using an Apparent Mass Tuned Viscous Mass Damper (Saito et al. 2008) Application of Tuned Viscous Mass Damper (Sugimura et al. 2012) Tuned Viscous Mass DamperTuned Mass Damper

19. Apparent Mass in Seismic Isolation Apparent Mass SDOF Base-isolated Building

20. Equation of Motion Apparent input ground motion reduces by. Note that it does not apply for acceleration.

21. An Issue the Previous Studies are Confronted by. Large floor response accelerations induced by the secondary apparent mass. To Overcome the Issue … Rotational friction mechanism is employed to restrict the excessive control force as well as to provide hysteretic energy dissipation to compensate the reduction of control force. (Nakaminami et al. 2012)

22. Analytical Model Considering Control Force Restriction Apparent Mass Force Limiter SDOF Base-isolated Building

23. Conclusions Brief review of response control of civil engineering structures using 2-node apparent mass devices is given. Presently, one of the most viable promising options to implement a 2-nodes apparent mass device is to utilize ball screw mechanism.

24. Than you for your kind attention.