Triply Coupled Vibration Band Gaps in Periodic Thin-Walled Open Cross Section Beams

Author(s):  
Dianlong Yu ◽  
Yaozong Liu ◽  
Jing Qiu ◽  
Gang Wang ◽  
Jihong Wen

Triply coupled vibration through periodic thin-walled open cross section nonsymmetrical beams composed of two kinds of material is studied in this paper. Based on the triply coupled vibration equation, plane wave expansion method for the thin-walled beams is provided. If the filling fraction keeps constant, the lattice is one of the factors that affect the normalized gap width. If the lattice and filling fraction keep constant, the Young’s modulus contrast plays a fundamental role for the band gap width, but not density contrast. Finally, the frequency response of a finite periodic binary beam is simulated with finite element method, which provides an attenuation of over 20dB in the frequency range of the band gaps. The findings will be significant in the application of phononic crystals.

2015 ◽  
Vol 29 (20) ◽  
pp. 1550105
Author(s):  
Haojiang Zhao ◽  
Rongqiang Liu ◽  
Chuang Shi ◽  
Hongwei Guo ◽  
Zongquan Deng

Longitudinal vibration of thin phononic crystal plates with a hybrid square-like array of square inserts is investigated. The plane wave expansion method is used to calculate the vibration band structure of the plate. Numerical results show that rotated square inserts can open several vibration gaps, and the band structures are twisted because of the rotation of inserts. Filling fraction and material of the insert affect the change law of the gap width versus the rotation angles of square inserts.


2005 ◽  
Vol 14 (8) ◽  
pp. 1501-1506 ◽  
Author(s):  
Yu Dian-Long ◽  
Liu Yao-Zong ◽  
Qiu Jing ◽  
Wang Gang ◽  
Wen Ji-Hong

2011 ◽  
Vol 675-677 ◽  
pp. 1085-1088
Author(s):  
Zong Jian Yao ◽  
Gui Lan Yu ◽  
Jian Bao Li

The band structures of flexural waves in a ternary locally resonant phononic crystal thin plate are studied using the improved plane wave expansion method. And the thin concrete plate composed of a square array of steel cylinders hemmed around by rubber is considered here. Absolute band gaps of flexural vibration with low frequency are shown. The calculation results show that the band gap width is strongly dependent on the filling fraction, the radius ratio, the mass density and the Young’s modulus contrasts between the core and the coating. So by changing these physical parameters, the required band gap could be obtained.


Author(s):  
Jihong Wen ◽  
Xisen Wen ◽  
Dianlong Yu

The flexural vibration band gaps in one-dimensional periodic sandwich beams with auxetic core are studied basing on the theory of Phononic crystals. The band structures of one-dimensional periodic sandwich beams with auxetic core are presented with the plane wave expansion method, the regular calculation method in phononic crystals. Further, the effects of material parameters and structure parameters on the gaps are analyzed. The vibration band gaps in the sandwich beams provide a new idea for the vibration controlling of the structure.


1981 ◽  
Vol 48 (1) ◽  
pp. 169-173 ◽  
Author(s):  
S. Narayanan ◽  
J. P. Verma ◽  
A. K. Mallik

Free-vibration characteristics of a thin-walled, open cross-section beam, with unconstrained damping layers at the flanges, are investigated. Both uncoupled transverse vibration and the coupled bending-torsion oscillations, of a beam of a top-hat section, are considered. Numerical results are presented for natural frequencies and modal loss factors of simply supported and clamped-clamped beams.


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