000013698 001__ 13698
000013698 005__ 20161114170252.0
000013698 04107 $$aeng
000013698 046__ $$k2011-05-25
000013698 100__ $$aSarlis, A.
000013698 24500 $$aNegative Stiffness Device for Seismic Protection of Structures - An Analytical and Experimental Study

000013698 24630 $$n3.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000013698 260__ $$bNational Technical University of Athens, 2011
000013698 506__ $$arestricted
000013698 520__ $$2eng$$aStructural weakening and damping is an approach previously proposed for the reduction of seismic forces and drifts in structures. While this approach is very efficient, it requires a reduction in strength, which will result in inelastic excursions and permanent deformation of the structural system during the seismic event. This paper describes a true Negative Stiffness Device (NSD) that can emulate weakening of the structural system without inelastic excursions and permanent deformations. The Negative Stiffness Device (NSD) is a self contained device that produces a force which is in the same direction as the imposed displacement, thus the name “negative stiffness”. The device is inherently unstable but when installed in a structure transfers a force at its installation level which in turn reduces all forces, drifts and accelerations above that level. The NSD is therefore capable of limiting the forces developed in a structure without any yielding which could lead to permanent deformations. The NSD was developed at the University at Buffalo (UB), Rice University and Taylor Devices Inc. and tested on a shake table by authors in a three storied structural model isolated with elastomeric bearings. The NSD consists of a highly compressed spring in a double negative stiffness magnification mechanism. In order to ensure a considerable amount of positive stiffness of the global system around small displacements to minimize wind vibrations a so called gap spring assembly (GSA) mechanism is implemented which delays the engagement of the device by a prescribed displacement. Moreover, the device employs double containment chevron braces that contain the large vertical forces needed for the development of negative stiffness without transferring these forces to the structure. This paper describes the development of analytical and computational tools that describe the behavior of the device and presents results for the experimental verification of these tools.

000013698 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000013698 653__ $$aNegative Stiffness Device, Apparent yielding, Passive, True Negative Stiffness

000013698 7112_ $$aCOMPDYN 2011 - 3rd International Thematic Conference$$cIsland of Corfu (GR)$$d2011-05-25 / 2011-05-28$$gCOMPDYN2011
000013698 720__ $$aSarlis, A.$$iPasala, D.$$iConstantinou, M.$$iReinhorn, A.$$iNagarajaiah, S.$$iTaylor, D.
000013698 8560_ $$ffischerc@itam.cas.cz
000013698 8564_ $$s3653473$$uhttps://invenio.itam.cas.cz/record/13698/files/536.pdf$$yOriginal version of the author's contribution as presented on CD, section: RS 10 Active - Passive  Control.
000013698 962__ $$r13401
000013698 980__ $$aPAPER