Global ETD Search
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Showing 1 to 10 of 10 for “"Negative stiffness"”.
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Development of a Novel Controllable Seismic Isolation System Based on Negative Stiffness Concept
… underwent by traditional adaptive seismic negative stiffness devices (ASNSDs) and other base isolators to contribute new knowledge to the seismic protection field. Firstly, the beneficial effects of nonlinear damping and stiffness on seismic protection are investigated in the form of …
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Extreme energy absorption : the design, modeling, and testing of negative stiffness metamaterial inclusions
… materials that simultaneously display high stiffness and high loss factors for the creation of structural elements capable of passively suppressing vibro-acoustic energy. Relevant recent research has shown that it is possible to produce composite materials whose macroscopic mechanical …
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Ruga mechanics of composite media with soft inclusions
… fibrils with soft inclusions exhibit negative post-buckling stiffness. The local instability is postulated to follow the same post- buckling behavior as a beam on an elastic foundation, through a semi-analytical approach, it is shown that an unstable post-bifurcation response emerges. …
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Computational and Experimental Nano Mechanics
… qualitative and quantitative measurements of the negative stiffness of a single crystal utilizing nano mechanical characterization; nano indentation. The concept of negative stiffness was first introduced by metastable structures and later by materials with negative stiffness when embedded in a …
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Passive vibration isolators with high-static-low-dynamic-stiffness
… isolation mount would have a high static stiffness to prevent too large a static displacement to occur, but a low dynamic stiffness which reduces the natural frequency and extends the frequency range of isolation. For linear mounts these two features are mutually exclusive. However, an …
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Towards programmable materials : tunable material properties through feedback control of conducting polymers
… as well as its material properties such as stiffness. Unlike muscle, current engineering materials are limited by their intrinsic properties, dictated at the molecular level.This work is focused on developing an integrated device, called a programmable material, which mirrors the …
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Developments on Electrodynamic Levitation of Rotors
… by an intrinsic stability problem related to negative stiffness. The alternative of superconducting bearings has to deal with the difficulties for guaranteeing low temperatures for the superconducting materials to work; this represents a barrier for this technology. In the last decades an …
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Morton Effect Induced Instability in Mid-Span Rotorâ Hydrodynamic Bearing Systems
… fact that the Morton Effect introduces either negative stiffness or negative cross-coupled stiffness. Next, the steady-state response performance under the influence of the Morton Effect is discussed. The results show that the Morton Effect has a comprehensive impact on both the amplitude and …
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Ultra-low and wide bandwidth vibrational energy harvesting using a statically balanced compliant mechanism
… This SBCM is designed based on the concept of stiffness compensation between a linear positive-stiffness component (two double parallelograms in parallel) and a nonlinear negative-stiffness component (two sets of post-buckled fixed-guided compliant beams in parallel). A design guideline of the …
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Performance assessment of special concentrically-braced frames in moderate seismic regions
… force resisting systems with high strength, stiffness, and material efficiency. Special concentrically-braced frame (SCBF) systems are a type of CBF commonly used in high seismic regions because they are designed to permit large inelastic drifts. Ductile detailing and capacity design …