Acoustic analysis of honeycomb sandwich structures with perforated septa and membrane‐type acoustic metamaterials.

2011 ◽  
Vol 129 (4) ◽  
pp. 2417-2417 ◽  
Author(s):  
Christina J. Naify ◽  
Chia‐Ming Chang ◽  
Geoffery McKnight ◽  
Steven Nutt
Keyword(s):  
Acoustic Analysis ◽  
Sandwich Structures ◽  
Acoustic Metamaterials ◽  
Honeycomb Sandwich ◽  
Membrane Type

Numerical and experimental investigation for enhancing the energy absorption capacity of the novel three-dimensional printed sandwich structures

2021 ◽  
pp. 146442072199749
Author(s):  
H Geramizadeh ◽  
S Dariushi ◽  
S Jedari Salami
Keyword(s):  
Energy Absorption ◽  
Sandwich Structures ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
The Novel ◽  
Energy Absorption Capacity ◽  
Fused Deposition ◽  
Honeycomb Sandwich ◽  
Out Of Plane ◽  
Vertical Walls

The current study focuses on designing the optimal three-dimensional printed sandwich structures. The main goal is to improve the energy absorption capacity of the out-of-plane honeycomb sandwich beam. The novel Beta VI and Alpha VI were designed in order to achieve this aim. In the Beta VI, the connecting curves (splines) were used instead of the four diagonal walls, while the two vertical walls remained unchanged. The Alpha VI is a step forward on the Beta VI, which was promoted by filleting all angles among the vertical walls, created arcs, and face sheets. The two offered sandwich structures have not hitherto been provided in the literature. All models were designed and simulated by the CATIA and ABAQUS, respectively. The three-dimensional printer fabricated the samples by fused deposition modeling technique. The material properties were determined under tensile, compression, and three-point bending tests. The results are carried out by two methods based on experimental tests and finite element analyses that confirmed each other. The achievements provide novel insights into the determination of the adequate number of unit cells and demonstrate the energy absorption capacity of the Beta VI and Alpha VI are 23.7% and 53.9%, respectively, higher than the out-of-plane honeycomb sandwich structures.

Microwave Absorbing Properties of Lightweight Nanocomposite/Honeycomb Sandwich Structures

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
A. A. Khurram ◽  
Sobia A. Rakha ◽  
Naveed Ali ◽  
M. T. Asim ◽  
Zhang Guorui ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Epoxy Composite ◽  
Sandwich Structures ◽  
Wide Band ◽  
Wide Frequency Range ◽  
Simulation Software ◽  
Multiwalled Carbon ◽  
Thin Glass ◽  
Honeycomb Sandwich ◽  
Honeycomb Cores

Thin glass-fiber/epoxy-composite sheets filled with multiwalled carbon nanotubes (MWCNTs) are manufactured to make lightweight honeycomb sandwich microwave absorbers. A multilayered sandwich structure of thin nanocomposite sheets and honeycomb spacers have been also proposed and developed to work in a wide frequency range. The nanocomposite sheets are prepared from 0.5, 1.0, 1.5, 2.0, and 2.5 wt. % of MWCNTs. A commercially available simulation software computer simulation technology (CST) microwave studio was used for the designing and development of radar absorbing structure (RAS) composed of MWCNTs/glass-fiber/epoxy-composite sheets and honeycomb cores. The measurements of return loss (RL) from sandwich structures with 5 mm and 20 mm honeycomb cores in the Ku band (11–17 GHz) show that maximum RL is achieved at 11 GHz and 16 GHz, respectively. The stacking of three nanocomposite sheets and three 5 mm-thick honeycomb spacers produced a wide band microwave absorber with −10 dB RL over 9 GHz bandwidth.

Adjustable sound insulation frequency band through the combination of membrane-type acoustic metamaterial array

2021 ◽  
Vol 263 (1) ◽  
pp. 5869-5877
Author(s):  
Xiang Wu ◽  
TengLong Jiang ◽  
JianWang Shao ◽  
GuoMing Deng ◽  
Chang Jin
Keyword(s):  
Thin Films ◽  
Frequency Band ◽  
Transmission Loss ◽  
Structural Parameters ◽  
Sound Insulation ◽  
Acoustic Metamaterials ◽  
Additional Mass ◽  
Acoustic Metamaterial ◽  
Material Parameters ◽  
Membrane Type

Membrane-type acoustic metamaterials are thin films or plates composed of periodic units with small additional mass. A large number of studies have shown that these metamaterials exhibit tunable anti-resonance, and their transmission loss values are much higher than the corresponding quality laws. At present, most researches on membrane-type acoustic metamaterials focus on the unit cell, and the sound insulation frequency band can only be adjusted by adjusting the structural parameters and material parameters. In this paper, two kinds of acoustic metamaterials with different structures are designed, which are the center placement of the mass and the eccentric placement of the mass.The two structures have different sound insulation characteristics. By designing different array combinations of acoustic metamaterials, the sound insulation peaks of different frequency bands are obtained. This paper studies the corresponding combination law, and effectively realizes the adjustable sound insulation frequency band.

Low frequency sound absorption of adjustable membrane-type acoustic metamaterials

2022 ◽  
Vol 188 ◽  
pp. 108586
Author(s):  
Tuo Xing ◽  
Xiaoling Gai ◽  
Junjuan Zhao ◽  
Xianhui Li ◽  
Zenong Cai ◽  
...  
Keyword(s):  
Sound Absorption ◽  
Low Frequency ◽  
Acoustic Metamaterials ◽  
Frequency Sound ◽  
Membrane Type

Membrane-Type Acoustic Metamaterials: Theory, Design, and Application

2015 ◽  
Author(s):  
Yangyang Chen ◽  
Rui Zhu ◽  
Huy Q. Nguyen ◽  
Guoliang Huang
Keyword(s):  
Acoustic Metamaterials ◽  
Membrane Type ◽  
Design And Application
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