The vibrational properties of a periodic composite pipe in 3D space

Piping system vibrations exist in many fields. Vibration control is very important because it can limit possible damage to pipe systems caused by vibrations. Applying the idea of the Bragg scattering mechanism of phononic crystals (PCs), a pipe is designed as a periodic composite material structure. Using the transfer matrix method, the band structure of an infinite periodic straight pipe structure is calculated. With knowledge of the vibration band gaps, a 3D space pipe system is designed with a composite material periodic structure, and its various vibration modes' frequency response functions are calculated. The accuracy of the transfer matrix method is verified with the commercial software MSC.Actran. The results show that the Bragg band gaps still exist in the 3D periodic pipe structure, and vibrations are strongly attenuated within the frequency ranges of the band gaps. Using the idea of PCs in piping systems provides a novel way to reduce pipe vibration. (C) 2009 Elsevier Ltd. All rights reserved.