000015695 001__ 15695
000015695 005__ 20161115135327.0
000015695 04107 $$aeng
000015695 046__ $$k2013-06-12
000015695 100__ $$aNielsen, R.
000015695 24500 $$aThe Wkb Approximation and Periodicity Effects for Perturbed Helical Springs

000015695 24630 $$n34.$$pComputational Methods in Structural Dynamics and Earhquake Engineering
000015695 260__ $$bNational Technical University of Athens, 2013
000015695 506__ $$arestricted
000015695 520__ $$2eng$$aPeriodic curvature in rods exposed to time harmonic loads have previously been studied by [1] with the aim to design stop and pass bands filters of an elastic waveguide. The structure was composed of segments with constant curvature and which enable the determination of the dispersions relations by standard methods. The conclusion drawn is that a relatively large insertion loss may be obtained with proper choice of curvatures. In the approach taken in this work the curvature in each period are taken as varying and thus the wave propagation in each period may be determined by the use of the WKB approximation provided that the curvature is only slowly changing. The methodology is applied to problems of helical springs that have periods with gradually changing curvature, and the periodicity effects may consequently be studied by classical Floquet theory. This proposed analysis facilitates the choice of the optimal curvature since the impact if this is clearer due to the use of the WKB approximation.

000015695 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000015695 653__ $$a

000015695 7112_ $$aCOMPDYN 2013 - 4th International Thematic Conference$$cIsland of Kos (GR)$$d2013-06-12 / 2013-06-14$$gCOMPDYN2013
000015695 720__ $$aNielsen, R.
000015695 8560_ $$ffischerc@itam.cas.cz
000015695 8564_ $$s34407$$uhttps://invenio.itam.cas.cz/record/15695/files/1275.pdf$$yOriginal version of the author's contribution as presented on CD, section: CD-MS 28 PERIODICITY EFFECTS AND PERIODICITY-BASED METHODS IN VIBRO-ACOUSTICS AND STRUCTURAL DYNAMICS
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000015695 962__ $$r15525
000015695 980__ $$aPAPER