Abolfathi, AliWaters, Tim P.Brennan, Michael J. [UNESP]2014-05-272014-05-272011-12-0118th International Congress on Sound and Vibration 2011, ICSV 2011, v. 4, p. 2960-2967.http://hdl.handle.net/11449/73043A nonlinear spring element of a vibration isolator should ideally possess high static and low dynamic stiffness. A buckled beam may be a good candidate to fulfil this requirement provided its internal resonance frequencies are high enough to achieve a wide frequency range of isolation. If a straight beam is used, there is a singularity in the force-displacement characteristic. To smooth this characteristic and eliminate the singularity at the buckling point, beams with initial constant curvature along their length are investigated here as an alternative to the buckled straight beam. Their force displacement characteristics are compared with different initial curvature and with a straight buckled beam. The minimum achievable dynamic stiffness with its corresponding static stiffness is compared for different initial curvatures. A case study is considered where the beams are optimized to isolate a one kilogram mass and to achieve a natural frequency of 1 Hz, considering small amplitudes of vibration. Resonance frequencies of the optimized beams for different curvature are presented. It is shown that an order of magnitude reduction in stiffness compared with a linear spring is achievable, while the internal resonance frequencies of the curved beam are high enough to achieve an acceptable frequency range of isolation.2960-2967engBuckled beamsConstant curvatureCurved beamsDynamic stiffnessForce-displacement characteristicsFrequency rangesInitial curvatureInternal resonanceLinear springMagnitude reductionNonlinear springsPassive vibrationResonance frequenciesSmall amplitudeStatic stiffnessVibration isolatorsWide frequency rangeBucklingCurved beams and girdersNatural frequenciesOptimizationStiffnessCurve fittingTrabalho apresentado em eventoAcesso aberto2-s2.0-84871521715