scholarly journals Flexural band gaps and vibration control of a periodic railway track

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohd Iqbal ◽  
Anil Kumar ◽  
Mahesh Murugan Jaya ◽  
Oreste Salvatore Bursi
Keyword(s):  
Vibration Control ◽  
Band Gap ◽  
Periodic Structures ◽  
Control Strategies ◽  
Gaussian White Noise ◽  
Railway Track ◽  
Flexural Wave ◽  
Gap Characteristics ◽  
Flexural Wave Propagation ◽  
Pass Through

AbstractPeriodic structures exhibit unique band gap characteristics by virtue of which they behave as vibro-acoustic filters thereby allowing only waves within a certain frequency range to pass through. In this paper, lateral and vertical flexural wave propagation and vibration control of a railway track periodically supported on rigid sleepers using fastenings are studied in depth. The dispersion relations in both lateral and vertical directions are obtained using the Floquet-Bloch theorem and the resulting dispersion curves are verified using finite element models. Afterwards, tuned mass dampers (TMDs) with different mass ratios are designed to control vibrations of the examined rail in both the directions. Moreover, the influence of damping of rail and resonators on band gap characteristics is investigated. As a replacement to the conventional TMD, a novel possibility to control vibration relies on using another existing rail as a lateral distributed resonator (LDR). Although the effectiveness of LDR is lower than that of localized resonators, the former represents a simple and promising way to control vibrations. Efficacy of the proposed control methods is finally verified by applying a random Gaussian white noise input. The study presented here is useful to understand the propagation and attenuation behavior of flexural waves and to develop efficient and novel vibration control strategies for track structures.

scholarly journals Flexural Band Gaps and Vibration Control of a Periodic Railway Track

2021 ◽  
Author(s):  
Mohd Iqbal ◽  
Anil Kumar ◽  
Mahesh Murugan Jaya ◽  
Oreste Salvatore Bursi
Keyword(s):  
Vibration Control ◽  
Periodic Structures ◽  
Gaussian White Noise ◽  
Railway Track ◽  
Flexural Wave ◽  
Acoustic Filters ◽  
Gap Characteristics ◽  
Flexural Wave Propagation ◽  
Noise Input ◽  
Pass Through

Abstract Periodic structures exhibit unique band gap characteristics by virtue of which they behave as vibro-acoustic filters thereby allowing only waves within a certain frequency range to pass through. In this paper, both lateral and vertical flexural wave propagation and vibration control of a periodic railway track are studied in depth. More precisely, a rail fastened on rigid sleeper blocks is modeled with an Euler-Bernoulli beam. The dispersion relations in both lateral and vertical directions are obtained using the Floquet-Bloch theorem and the resulting dispersion curves are verified using finite element (FE) models. Afterwards, tuned mass dampers (TMDs) with different mass ratios are designed to control vibrations of the examined rail along both lateral and vertical directions. Moreover, the influence of damping of rail and resonators on band structures is investigated. As a replacement to the conventional TMD, a novel possibility to control vibrations relies on using another rail as a lateral distributed resonator (LDR). Although the effectiveness of LDR is lower than that of localized resonators, the former represents a simple and promising way to control vibrations. Efficacy of the proposed control methods is finally verified using the results of transient simulation based on a random Gaussian white noise input.

scholarly journals Low frequency band gap characteristics of double-split Helmholtz locally resonant periodic structures

2017 ◽  
Vol 66 (6) ◽  
pp. 064301
Author(s):  
Jiang Jiu-Long ◽  
Yao Hong ◽  
Du Jun ◽  
Zhao Jing-Bo ◽  
Deng Tao
Keyword(s):  
Band Gap ◽  
Frequency Band ◽  
Periodic Structures ◽  
Low Frequency ◽  
Gap Characteristics

Investigations on the band-gap characteristics of one-dimensional flexural periodic structures with varying geometries

2021 ◽  
pp. 107754632110368
Author(s):  
Sachchidanand Das ◽  
Murtaza Bohra ◽  
Sabareesh Geetha Rajasekharan ◽  
Yendluri Venkata Daseswara Rao
Keyword(s):  
Band Gap ◽  
Frequency Band ◽  
Periodic Structures ◽  
Band Gaps ◽  
One Dimensional ◽  
Vibration Attenuation ◽  
Gap Characteristics ◽  
Novel Concept ◽  
Selection Of ◽  
Shape And Size

Periodic structures have been studied extensively for their wave-filtering capabilities as they exhibit frequency band-gaps. The band-gap characteristics of flexural periodic structures, consisting of periodic cavities, depend on the geometry (shape and size) of cavities. The present work brings out experimental and numerical investigation of the effect of geometry of periodicity on the vibration characteristics of one-dimensional periodic structures. A procedure for prediction of the experimentally observed frequency band-gaps, with the help of eigenfrequency analysis, has been presented. Further, a novel concept of ‘real’ and ‘pseudo’ band-gaps has been theorized. Based on the experimental and numerical results, the best configuration of a periodic structure for maximum vibration attenuation has been arrived at. The work can find application in the design of frames and channels, made of periodic structures, where periodicity can be introduced to reduce vibration transmission in desired frequency bands. It can also reduce the requirement of extensive prototype trials for the selection of suitable periodic geometry.

scholarly journals Low-frequency broadband vibration attenuation of sandwich plate-type metastructures with periodic thin-wall tube cores

2021 ◽  
pp. 146134842110355
Author(s):  
Huan Zi ◽  
Yinggang Li
Keyword(s):  
Wave Propagation ◽  
Band Gap ◽  
Sandwich Plate ◽  
Low Frequency ◽  
Flexural Wave ◽  
Wave Band ◽  
Thin Wall ◽  
Vibration Attenuation ◽  
Flexural Wave Propagation ◽  
Plate Type

Sandwich structures are widely applied in modern industry such as aerospace, automobile as well as marine structures. However, the vibroacoustic properties of sandwich structures are adversely influenced by low effective mass. In this study, the flexural wave propagation characteristics and vibration mitigation performances of the periodic sandwich plate-type metastructures are investigated. The proposed sandwich plate-type metastructures are constituted of a sandwich plate with periodic thin-wall circular tube cores and periodically attached local stepped resonators. A finite element method combining Solid-Shell coupling numerical method and Bloch theory is presented to calculate the dispersion relations and the displacement fields of the eigenmodes of the infinite periodic sandwich plate-type metastructures. In addition, the acceleration frequency responses and vibration attenuation performances of finite periodic sandwich plate-type metastructures are numerically investigated and compared with the experimental measurements. Furthermore, the influences of geometric parameters on flexural wave band gaps are conducted. Results show that the sandwich plate-type metastructures can yield a low-frequency broad flexural wave band gap, in which the flexural wave propagation is conspicuously suppressed, resulting in significant flexural vibration attenuation. The flexural wave band gap and vibration attenuation performances can be effectively manipulated by designing geometric parameters of the sandwich plate-type metastructures.

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