# Time-Periodic Stiffness Modulation in Elastic Metamaterials for Selective Wave Filtering: Theory and Experiment.

@article{Trainiti2019TimePeriodicSM, title={Time-Periodic Stiffness Modulation in Elastic Metamaterials for Selective Wave Filtering: Theory and Experiment.}, author={G. Trainiti and Yiwei Xia and J. Marconi and Gabriele Cazzulani and Alper Erturk and Massimo Ruzzene}, journal={Physical review letters}, year={2019}, volume={122 12}, pages={ 124301 } }

Elastic waveguides with time-modulated stiffness feature a frequency-periodic dispersion spectrum, where branches merge at multiple integers of half the modulation frequency and over a finite wave number range. In this range, frequency becomes complex, with its real part remaining constant. The vanishing group velocity associated with these flat bands leads to frequency-selective reflection at an interface between a nonmodulated medium and a time-modulated one, which converts a broadband input…

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