Abstract
Novel metamaterial concepts can be used to economically reduce flexural vibrations in coupled pipe-rack systems. Here, we model pipe on flexible supports as periodic systems and formulate dispersion relations using Floquet-Bloch theory which is verified by a finite element model. Owing to the flexibility of the coupled system, a narrow pass band is created in low frequency regime, in contrast to the case of pipe without any rack. Two types of vibration reduction mechanisms are investigated for pipe with different supports, i.e. simple and elastic support. In order to tune the band gap behaviour, lateral localized resonators are attached at the centre of each unit cell; conversely, the lateral distributed resonators are realized with a secondary pipe existing in the system. The results reveal that both Bragg and resonance type band gaps coexist in piping systems due to the presence of spatial periodicity and local resonance. Although, the response attenuation of a coupled pipe-rack system with distributed resonators is found to be little lower than the case with the localized one, the relatively low stiffness and damping values lead to cheaper solutions. Therefore, the proposed concept of distributed resonators represents a promising application in piping, power and process industries.
Highlights
Novel metamaterial concepts can be used to economically reduce flexural vibrations in coupled piperack systems
In order to reduce flexural vibrations in coupled pipe-rack systems of liquefied natural gas (LNG) plants, novel and economic ways based on metamaterial concepts are proposed
The adoption of localized resonators (LLRs) without damping entails a new band gap located near the natural frequency of LLRs which can be observed in both Fig. 5a,b for Type #1 and Type #2 support, respectively
Summary
Novel metamaterial concepts can be used to economically reduce flexural vibrations in coupled piperack systems. Periodicity in a structure may be in one, two or in all the three dimensions[6] Such systems exhibit unique frequency band gap characteristics[3], which can be generated either due to the Bragg scattering[6,7] or by local resonances[8]. In order to filter undesired longitudinal[17], flexural[18,19,20,21,22,23,24,25,26] or torsional[27,28] waves, a periodic structure can be equipped with resonator units that entail new band gaps different from those produced by Bragg scattering[7].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
