A Study on Response Control Efficacy By Using Rotary Inertia Mass Damper Filled With Magneto-Rheological Fluid


Abstract eng:
This paper relates to response control of a base-isolated structure with a hybrid vibration device (“MR rotary inertia damper”) aiming at two purposes: 1) mass effects with rotary inertia and 2) variable damping effects with magnetorheological fluid, developed by authors in order to control vibration response to earthquakes. Our goal is to propose a method to reduce response displacement of seismic floor by controlling floor response acceleration with semi-active control toward various earthquakes that generally used for aseismic design in Japan. Based on these results, a vibration analysis model is proposed in this paper with performance tests of the MR rotary inertia damper as a semi-active vibration control device, to review frequency characteristics and propose a semi-active control with a skyhook method. Response control effects of the MR rotary inertia damper to earthquakes are discussed with time-history response analysis in regards to the control method proposed. Findings obtained in this paper are the following. In performance tests of the MR rotary inertia damper, a prototype with the maximum output of 100kN was prepared and the basic characteristics were summarized by using a vibration test with displacement input of an actuator, to verify adequacy of theoretical formulas. Energy absorption effects with resistance to shear flow of MR fluid as well as with yield stress upon magnetic field action were confirmed in the sin-wave input tests, to indicate the effectiveness as a semi-active control device that uses variable damping force. Based on the performance tests of the MR rotary inertia damper, we review the seismic isolation model, from the viewpoint of transfer function in the frequency range as well as of time-history response to earthquake motions. The range that can reduce both acceleration transmission and displacement transmission by adopting a proper mass ratio is suggested from the transfer function in the frequency range. However, there are advantages and disadvantages in the mass ratio and damping ratio, and we suggest that their tradeoff relationship cannot be resolved only with passive control. By adopting the skyhook method toward this problem, we suggest the possibility of reducing the transmission adjacent to the resonance frequency without deteriorating the transmission in the high frequency range. In addition, it is clarified from the review on time-history response that the floor response acceleration can be effectively reduced in the case of pulse earthquakes particularly with major vibration with 1-2 seconds period by adopting a proper mass ratio and damping ratio. At the time of passive control, semi-active control effects on each input earthquake motion were identified in the case of combination of mass ratio and damping ratio that minimizes the maximum floor response acceleration, confirming that the maximum floor response acceleration and the maximum response displacement can be reduced by approximately 1% and 30% on average, respectively. It was concluded in accordance with these results that the semi-active control method that incorporates inertia mass effects proposed in this paper is effective to control the floor response acceleration while reducing the response displacement of seismic floor at the same time.

Contributors:
Conference Title:
Conference Title:
16th World Conference on Earthquake Engineering
Conference Venue:
Santiago (CL)
Conference Dates:
2017-01-09 / 2017-01-13
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.



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 Record created 2017-01-18, last modified 2017-01-18


Original version of the author's contribution as presented on USB, paper 3155.:
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