Dual-tuning mechanism for elastic wave transmission in a triatomic lattice with string stiffening

We investigate the effect of taut strings with adjustable tensions, on the frequency spectra for elastic waves transmission in the triatomic lattice. The wave equations of a triatomic chain with tensioned strings are first developed through the lattice dynamics. The tunable string stiffness is derived from modal separation. Subsequently, the dispersion relations of such system are evaluated using both the linearized model and the perturbation approach, respectively. It is shown that the bandgaps become wider as greater tensions are exerted. Also, string-tuning bandgaps can exhibit non-Hermitian form in multi-atomic lattices. Transmission properties and energy distribution of the corresponding finite system composed of such basic units are further analyzed. When high-amplitude wave enters with strings tightened, the dual-tuning effect of the tension and vibrational amplitude on bandgaps has been noticed simultaneously. The present work could help in understanding the physics of periodic multi-atomic lattices with strings and sheds light on wave blocking and filtering. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the effect of taut strings with adjustable tensions on the frequency spectra for elastic waves transmission in a triatomic lattice. The results show that the bandgaps become wider as greater tensions are exerted, and the string-tuning bandgaps can exhibit non-Hermitian form in multi-atomic lattices. The transmission properties and energy distribution of the corresponding finite system composed of such basic units are also analyzed. It is found that when high-amplitude waves enter with strings tightened, the tension and vibrational amplitude have a dual-tuning effect on the bandgaps.