The Effect of Honeycomb Core Geometry on the Sound Transmission Performance of Sandwich Panels

2014 ◽  
Author(s):  
David Griese ◽  
Joshua D. Summers ◽  
Lonny Thompson
Keyword(s):  
Sandwich Panels ◽  
Sound Transmission ◽  
Honeycomb Core ◽  
Transmission Performance

Sound transmission loss characteristics of sandwich aircraft panels: Influence of nature of core

2016 ◽  
Vol 19 (1) ◽  
pp. 26-48 ◽  
Author(s):  
MP Arunkumar ◽  
Jeyaraj Pitchaimani ◽  
KV Gangadharan ◽  
MC Lenin Babu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sheet Material ◽  
Low Frequency ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Honeycomb Core ◽  
Transmission Characteristics ◽  
The Impact

Sandwich panel which has a design involving acoustic comfort is always denser and larger in size than the design involving mechanical strength. The respective short come can be solved by exploring the impact of core geometry on sound transmission characteristics of sandwich panels. In this aspect, the present work focuses on the study of influence of core geometry on sound transmission characteristics of sandwich panels which are commonly used as aircraft structures. Numerical investigation has been carried out based on a 2D model with equivalent elastic properties. The present study has found that, for a honeycomb core sandwich panel in due consideration to space constraint, better sound transmission characteristics can be achieved with lower core height. It is observed that, for a honeycomb core sandwich panel, one can select cell size as the parameter to reduce the weight with out affecting the sound transmission loss. Triangular core sandwich panel can be used for low frequency application due to its increased transmission loss. In foam core sandwich panel, it is noticed that the effect of face sheet material on sound transmission loss is significant and this can be controlled by varying the density of foam.

scholarly journals Vibration and Sound Transmission Performance of Sandwich Panels with Uniform and Gradient Auxetic Double Arrowhead Honeycomb Cores

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Qing Li ◽  
Deqing Yang
Keyword(s):  
Transmission Loss ◽  
Sandwich Structures ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Bending Stiffness ◽  
Mode Shapes ◽  
Sound Insulation ◽  
Transmission Performance ◽  
Constant Weight ◽  
Honeycomb Sandwich

Auxetic mechanical metamaterials that exhibit a negative Poisson’s ratio (NPR) can be artificially designed to exhibit a unique range of physical and mechanical properties. Novel sandwich structures composed of uniform and gradient auxetic double arrowhead honeycomb (DAH) cores were investigated in terms of their vibration and sound transmission performance stimulated by nonhomogeneous metamaterials with nonperiodic cell geometries. The spectral element method (SEM) was employed to accurately evaluate the natural frequencies and dynamic responses with a limited number of elements at high frequencies. The results indicated that the vibrating mode shapes and deformations of the DAH sandwich models were strongly affected by the patterned gradient metamaterials. In addition, the sound insulation performance of the considered DAH sandwich models was investigated regarding the sound transmission loss (STL) from 1 Hz to 1500 Hz under a normal incident planar wave, and this performance was compared with that for hexagonal honeycomb sandwich panels. A programmable structural-acoustic optimization was implemented to maximize the STL while maintaining a constant weight and high strength. The results showed that the uniform DAH sandwich models with larger NPRs generally exhibited better vibration and acoustic attenuation behaviors and that the optimized gradient increasing NPR models yielded higher STL values than the optimized gradient decreasing NPR models for two specified frequency cases, with improvements of 6.52 dB and 2.52 dB and a higher bending stiffness but a lower overall STL. Thus, sandwich panels consisting of auxetic DAHs can achieve desirable vibroacoustic performance with a higher bending stiffness than conventional hexagonal honeycomb sandwich structures, and the design of gradient DAHs can be extended to obtain optimized vibration and noise-control capabilities.

Impact Analysis of Honeycomb Core Sandwich Panels

2020 ◽  
Author(s):  
Shah Alam ◽  
Damodar Khanal
Keyword(s):  
Sandwich Panels ◽  
Sheet Thickness ◽  
Composite Panel ◽  
Face Sheet ◽  
Impact Behavior ◽  
Front Face ◽  
Geometrical Parameters ◽  
Honeycomb Core ◽  
Back Face ◽  
The Impact

Abstract The goal of this paper is to analyze the impact behavior among geometrically different sandwich panels shown upon impact velocities. Initially, composite model with aluminum honeycomb core and Kevlar (K29) face sheets is developed in ABAQUS/Explicit and different impact velocities are applied. Keeping other parameters constant, model is simulated with T800S/epoxy face sheets. Residual velocities, energy absorption (%), and maximum deformation depth is calculated for sandwich panel for both models at five different velocities by executing finite element analysis. Once the better material is found for face sheets, process is extended by varying the ratio of front face sheet thickness to back face sheet thickness keeping other geometrical parameters constant to find the better geometry. Also, comparison of impact responses of sandwich composite panel on different ratio of front face sheet thickness to back face sheet thickness is done and validated with other results available in literature.

scholarly journals The Bending Responses of Sandwich Panels with Aluminium Honeycomb Core and CFRP Skins Used in Electric Vehicle Body

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong Xiao ◽  
Yefa Hu ◽  
Jinguang Zhang ◽  
Chunsheng Song ◽  
Xiangyang Huang ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Vehicle Body ◽  
Stacking Sequence ◽  
Honeycomb Core ◽  
Fibre Direction ◽  
Element Analysis ◽  
Honeycomb Sandwich ◽  
Carbon Fibre Reinforced Plastic

The aim of this paper was to investigate bending responses of sandwich panels with aluminium honeycomb core and carbon fibre-reinforced plastic (CFRP) skins used in electric vehicle body subjected to quasistatic bending. The typical load-displacement curves, failure modes, and energy absorption are studied. The effects of fibre direction, stacking sequence, layer thickness, and loading velocity on the crashworthiness characteristics are discussed. The finite element analysis (FEA) results are compared with experimental measurements. It is observed that there are good agreements between the FEA and experimental results. Numerical simulations and experiment predict that the honeycomb sandwich panels with ±30° and ±45° fibre direction, asymmetrical stacking sequence (45°/−45°/45°/−45°), thicker panels (0.2 mm∼0.4 mm), and smaller loading velocity (5 mm/min∼30 mm/min) have better crashworthiness performance. The FEA prediction is also helpful in understanding the initiation and propagation of cracks within the honeycomb sandwich panels.

Prediction of Sound Transmission Loss for Finite Sandwich Panels Based on a Test Procedure on Beam Elements

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zhongchang Qian ◽  
Daoqing Chang ◽  
Bilong Liu ◽  
Ke Liu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Test Procedure ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Expansion Method ◽  
Bending Stiffness ◽  
Sound Transmission Loss ◽  
Modal Expansion ◽  
Beam Elements

An approach on the prediction of sound transmission loss for a finite sandwich panel with honeycomb core is described in the paper. The sandwich panel is treated as orthotropic and the apparent bending stiffness in two principal directions is estimated by means of simple tests on beam elements cut from the sandwich panel. Utilizing orthotropic panel theory, together with the obtained bending stiffness in two directions, the sound transmission loss of simply-supported sandwich panel is predicted by the modal expansion method. Simulation results indicated that dimension, orthotropy, and loss factor may play important roles on sound transmission loss of sandwich panel. The predicted transmission loss is compared with measured data and the agreement is reasonable. This approach may provide an efficient tool to predict the sound transmission loss of finite sandwich panels.

Effective Mechanical Behavior of Sandwich Beams under Uncoupled Bending and Torsion Loadings

2014 ◽  
Vol 590 ◽  
pp. 58-62 ◽  
Author(s):  
Hugo Miguel Silva ◽  
José Filipe Bizarro de Meireles
Keyword(s):  
Mechanical Behavior ◽  
Design Optimization ◽  
Sandwich Panels ◽  
Sandwich Beams ◽  
Honeycomb Core ◽  
Low Intensity ◽  
Specific Stiffness ◽  
Low Weight ◽  
Structural Applications ◽  
Non Linear

Sandwich geometries, mainly panels and beams are widely used in several transportation industries, namely aerospace, aeronautic and automotive. Sandwich geometries are known for their advantages in structural applications: high specific stiffness, low weight, and possibility of design optimization prior to manufacturing. This study aims to know the influence of the number of reinforcements (ribs), and of the thickness on the mechanical behavior of sandwich panels subjected to bending and torsion loads separately. In this study, 3 geometries are compared: simple web-core beam, corrugated core, and honeycomb core. The last 2 are asymmetric, due to the use of odd number of ribs. The influence of the geometry on the results is discussed, by means of a parameter that establishes a relation between the stiffness behavior and the mass of the object. It is shown that the all relations are non-linear, despite the elastic nature of the analysis, by means of the application of loads with low intensity.

scholarly journals Ballistic Resistance of Honeycomb Sandwich Panels under In-Plane High-Velocity Impact

2013 ◽  
Vol 2013 ◽  
pp. 1-20 ◽  
Author(s):  
Chang Qi ◽  
Shu Yang ◽  
Dong Wang ◽  
Li-Jun Yang
Keyword(s):  
Structural Parameters ◽  
Sandwich Panels ◽  
Unit Cell ◽  
Dynamic Responses ◽  
Honeycomb Core ◽  
Ballistic Resistance ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Parametric Studies ◽  
Nonmonotonic Effects

The dynamic responses of honeycomb sandwich panels (HSPs) subjected to in-plane projectile impact were studied by means of explicit nonlinear finite element simulations using LS-DYNA. The HSPs consisted of two identical aluminum alloy face-sheets and an aluminum honeycomb core featuring three types of unit cell configurations (regular, rectangular-shaped, and reentrant hexagons). The ballistic resistances of HSPs with the three core configurations were first analyzed. It was found that the HSP with the reentrant auxetic honeycomb core has the best ballistic resistance, due to the negative Poisson’s ratio effect of the core. Parametric studies were then carried out to clarify the influences of both macroscopic (face-sheet and core thicknesses, core relative density) and mesoscopic (unit cell angle and size) parameters on the ballistic responses of the auxetic HSPs. Numerical results show that the perforation resistant capabilities of the auxetic HSPs increase as the values of the macroscopic parameters increase. However, the mesoscopic parameters show nonmonotonic effects on the panels' ballistic capacities. The empirical equations for projectile residual velocities were formulated in terms of impact velocity and the structural parameters. It was also found that the blunter projectiles result in higher ballistic limits of the auxetic HSPs.

An Experimental Study on a Novel Cladding System with Aluminium Honeycomb Core

2011 ◽  
Vol 261-263 ◽  
pp. 770-774
Author(s):  
Dong Ruan ◽  
Mohd Azman Yahaya ◽  
James Hicks ◽  
Jayson Lloyd ◽  
Feng Zhu
Keyword(s):  
Experimental Study ◽  
Cell Size ◽  
Mechanical Response ◽  
Sandwich Panels ◽  
Foil Thickness ◽  
Honeycomb Core ◽  
Impact Pulse ◽  
Blast Loadings

Sandwich panels consisting of two aluminium two face-sheets and a core made of aluminium honeycomb were studied in this paper. These sandwich panels are good candidates for cladding systems employed to protect other structures again blast loadings. In this paper, the mechanical response and deformation of these sandwich panels subjected to simulated blast loadings are investigated experimentally. The effects of impact pulse, foil thickness and cell size of aluminium honeycombs have been discussed.

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