کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
266398 504358 2015 23 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Inner pounding control of the RNC isolator and its impact on seismic isolation efficiency under near-fault earthquakes
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات مهندسی ژئوتکنیک و زمین شناسی مهندسی
پیش نمایش صفحه اول مقاله
Inner pounding control of the RNC isolator and its impact on seismic isolation efficiency under near-fault earthquakes
چکیده انگلیسی


• I present a device to protect structures under severe near-fault earthquakes.
• I developed a handy SAP2000 model of the device that considers all its features.
• I studied the possibly developed inner impact of the device due to self-stopping.
• I studied the influence of the inner impact of the device on isolation efficiency.
• Negative pounding influence is efficiently improved by passive and active control.

The recently proposed Roll-in-Cage (RNC) isolator, with an inherent self-stopping mechanism, is used herein for protection against near-fault earthquakes and to accommodate the expected large isolator displacement without using larger isolators nor bigger seismic gaps. The buffer mechanism is designed to draw any possible seismic pounding of a RNC-isolated superstructure downward to take place only within the RNC isolator’s bounds. The study investigates how to alleviate possibly arising unwanted effects due to such inner RNC isolator pounding by using passive and active feedback control. The inner isolator’s pounding is first controlled passively using more added hysteretic damping. Then, active feedback control forces are integrated to the purely passive RNC isolator to form a hybrid isolation system. The active control forces are intended to alleviate the isolator’s inner pounding through reducing the velocity of the isolated structure before the activation of the isolator’s self-stopping mechanism. The results show that the developed isolator’s inner pounding may deteriorate isolation efficiency, in terms of amplified peak structural accelerations, but such deterioration can be efficiently improved. The use of passive and hybrid strategies to control the inner RNC isolator’s pounding in this paper were found able to reduce, or even eliminate, pounding severity. However, active control forces decrease the degree of structure-ground decoupling causing less efficient isolation, contrary to the passive control of pounding using added hysteretic damping, which was found to be a more practical and more efficient solution. Moreover, it was found that the rolling-based RNC isolator is able to provide efficient anti-seismic protection even at relatively small isolation periods, besides its ability to be optimized to provide efficient seismic isolation with absolutely no inner pounding under strong ground motions, considering small bearing’s design displacements.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Engineering Structures - Volume 86, 1 March 2015, Pages 99–121
نویسندگان
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