000018758 001__ 18758
000018758 005__ 20170118182240.0
000018758 04107 $$aeng
000018758 046__ $$k2017-01-09
000018758 100__ $$aKeivan, Ashkan
000018758 24500 $$aSemi-Active Approximation of Rate-Independent Linear Damping for the Seismic Protection of Low-Frequency Structures

000018758 24630 $$n16.$$pProceedings of the 16th World Conference on Earthquake Engineering
000018758 260__ $$b
000018758 506__ $$arestricted
000018758 520__ $$2eng$$aRate-independent linear damping, also known as linear hysteretic damping or complex-value stiffness, provides direct control over displacement, a desirable feature for low-frequency structures. The greatest benefit is realized when the frequency of the input is larger than the frequency of the structure, typical of low-frequency structures under earthquake excitations. In such scenarios, rate-independent linear damping provides comparable reduction in displacement and velocity as other damping types with greater acceleration reduction and at about half of the restoring force. In rate-independent linear damping, the restoring force is proportional to displacement but in phase with velocity, leading to its non-causality. Numerical investigations have illustrated the promise of rate-independent linear damping through non-causal time-domain and frequency-domain analyses. However, there are limited practical approaches to determine the rate-independent force through causal analysis. Causal determination of the force associated with rate-independent linear damping will facilitate the realization of this force through semi-active or active control methods. This study proposes a filter-based approach to approximate rate-independent linear damping. The filter is used to approximate the preceded displacement, which is by definition proportional to the desired force. A semi-active control algorithm is then used to track the desired force. The approach is demonstrated for a hybrid base-isolation system with a magnetorheological damper incorporated in isolation layer of a base-isolated structure. Both numerical and experimental tests are conducted to examine the performance of this method to achieve the ideal damping force. Results compare very well with non-causal numerical simulations, confirming both through simulation and experimentation the proposed approach to achieve the benefits of rate-independent linear damping in practical structures.

000018758 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000018758 653__ $$arate-independent linear damping; base isolation; structural control

000018758 7112_ $$a16th World Conference on Earthquake Engineering$$cSantiago (CL)$$d2017-01-09 / 2017-01-13$$gWCEE16
000018758 720__ $$aKeivan, Ashkan$$iPhillips, Brian$$iIkenaga, Masahiro$$iIkago, Kohju
000018758 8560_ $$ffischerc@itam.cas.cz
000018758 8564_ $$s1465028$$uhttps://invenio.itam.cas.cz/record/18758/files/2169.pdf$$yOriginal version of the author's contribution as presented on USB, paper 2169.
000018758 962__ $$r16048
000018758 980__ $$aPAPER