Frontiers of Structural and Civil Engineering
>> 2016,
Volume 10,
Issue 3
doi:
10.1007/s11709-016-0346-x
RESEARCH ARTICLE
Experimental study of the restoring force mechanism in the self-centering beam (SCB)
Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 2406, USA
Accepted: 2016-08-10
Available online: 2016-10-25
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Abstract
In the past, several self-centering (SC) seismic systems have been developed. However, examples of self-centering systems used in practice are limited due to unusual field construction practices, high initial cost premiums and deformation incompatibility with the gravity framing. A self centering beam moment frame (SCB-MF) has been developed that mitigates several of these issues while adding to the advantages of a typical SC system. The self-centering beam (SCB) is a shop-fabricated, self-contained structural component that when implemented in a moment resisting frame can bring a building back to plumb after an earthquake. This paper describes the SCB concepts and experimental program on five SCB specimens at two-third scale relative to a prototype building. Experimental results are presented including the global force-deformation behavior. The SCBs are shown to undergo 5%–6% story drift without any observable damage to the SCB body and columns. Strength equations developed for the SCB predict the moment capacity well, with a mean difference of 6% between experimental and predicted capacities. The behavior of the restoring force mechanism is described. The limit states that cause a loss in system's restoring force which lead to a decrease in the self-centering capacity of the SCB-MF, are presented.