Vibro-acoustical responses of a sandwich panel consist of aluminum honeycomb core and fabric-reinforced graphite facings

2021 ◽  
pp. 109963622098246
Author(s):  
Luyao Wang ◽  
Liming Dai
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sandwich Structures ◽  
Numerical Study ◽  
The Other ◽  
Honeycomb Core ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Honeycomb Sandwich Structure ◽  
Composite Face

This research presents a numerical study on vibro-acoustic and sound transmission loss behavior of an aluminum honeycomb core sandwich panel with fabric-reinforced graphite (FRG) composite face sheets. The sandwich theory, which assumes the honeycomb core as an orthotropic structural layer, is applied to investigate the free and forced vibration behavior of the panel. The radiated sound power from the panel is quantified by Rayleigh integral method, and the random diffuse field as an incident sound source is derived based on finite element method with the employment of ACTRAN. A validation between the simulated results and the experimental data published is carried out to demonstrate the accuracy and reliability of the present approach. The comparison between different materials of honeycomb sandwich structures illustrates the advantages of the fabric-reinforced graphite honeycomb sandwich structure over the other types of sandwich structures considered. The effects of different boundary conditions and honeycomb structural geometry properties on the acoustical performance of the stiffness of the FRG panel are also investigated. The approach of the present research provides useful guidance for evaluating and selecting the other honeycomb sandwich panels when the vibratory and acoustic behaviors of the panels are considered.

Ballistic performance of honeycomb sandwich structures reinforced by functionally graded face plates

2017 ◽  
Vol 21 (1) ◽  
pp. 211-229 ◽  
Author(s):  
Recep Gunes ◽  
Kemal Arslan ◽  
M Kemal Apalak ◽  
JN Reddy
Keyword(s):  
Sandwich Structure ◽  
Sandwich Structures ◽  
Threshold Energy ◽  
Functionally Graded ◽  
Honeycomb Core ◽  
Ballistic Performance ◽  
Damage Area ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb ◽  
Honeycomb Sandwich Structure

This study investigates damage mechanisms and deformation of honeycomb sandwich structures reinforced by functionally graded face plates under ballistic impact. The honeycomb sandwich structure consists of two identical functionally graded face sheets, having different material compositions through the thickness, and an aluminum honeycomb core. The functionally graded face sheets consist of ceramic (SiC) and aluminum (Al 6061) phases. The through-thickness mechanical properties of face sheets are assumed to vary according to a power-law. The locally effective material properties are evaluated using the Mori–Tanaka scheme. The effect of material composition of functionally graded face sheets on the ballistic performance of honeycomb sandwich structures was investigated using the finite element method and the penetration and perforation threshold energy values on ballistic performance and ballistic limit of the sandwich structures are determined. The contribution of the honeycomb core on the ballistic performance of the sandwich structure was evaluated by comparing with spaced plates (without honeycomb core) in terms of the residual velocity, kinetic energy, and damage area.

Detection of Unbonds in Honeycomb Sandwich Structure Using Lock-In Thermography

2010 ◽  
Vol 97-101 ◽  
pp. 4363-4366
Author(s):  
Hui Liu ◽  
Jun Yan Liu ◽  
Yang Wang ◽  
Hui Juan Li
Keyword(s):  
Sandwich Structure ◽  
Sandwich Structures ◽  
Modulation Frequency ◽  
Influencing Factor ◽  
Face Sheet ◽  
Honeycomb Core ◽  
Honeycomb Sandwich ◽  
Testing Technology ◽  
Lock In ◽  
Honeycomb Sandwich Structure

Lock-in thermography (LT), that is active infrared testing technology, mainly includes optical lock-in thermography (OLT) and ultrasound lock-in thermography (ULT). LT can be used to detect unbonds between honeycomb core and face sheet of sandwich structures. However, modulation frequency is an important influencing factor. In this paper, the principles of LT are represented, in experimental detections of simulated unbonds in honeycomb sandwich structures with Al-face sheet and CFRP-face sheet using OLT and ULT, detectability of OLT and ULT is compared and analyzed, effect of modulation frequency is researched and the optimal frequencies are obtained.

Experimental and numerical study for effective thermal conductivity of metallic honeycomb sandwich structures

2020 ◽  
pp. 109963622093353
Author(s):  
Rongnan Yuan ◽  
Shouxiang Lu
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Sandwich Structure ◽  
Sandwich Structures ◽  
Numerical Study ◽  
Heat Transfer Process ◽  
Heat Radiation ◽  
Honeycomb Sandwich ◽  
Essential Parameter ◽  
Honeycomb Sandwich Structure

Effective thermal conductivity is an essential parameter to investigate thermal properties of metallic honeycomb sandwich structures. And it cannot be measured by traditional methods due to sandwich structure imbedded with air. A practical experimental equipment was designed to evaluate the value under different temperature from 100°C to 400°C. And it was found that the value of effective thermal conductivity can also be calculated by knowing the thermal conductivity of the reference, thickness of the reference and the slope and intercept of temperature in different layers. Meanwhile, numerical simulation was conducted and the results agreed well with that achieved by experiment. Also, the value of effective thermal conductivity calculated by experiment is close to the value calculated by Swann-Pittman empirical equation. And the method is not limited in metallic honeycomb sandwich structure while it can be applied in most structures with amounts of air. On that basis, heat transfer process of the structure is discussed including heat conduction, heat convection and heat radiation.

Debonding Detection at Core/Skin Interfaces in a Honeycomb Sandwich Structure Using a Laser Ultrasonic Visualization Method

2020 ◽  
Author(s):  
Enhi Sen ◽  
Osamu Saito ◽  
Nobuhiro Higuchi ◽  
Yoji Okabe
Keyword(s):  
Laser Irradiation ◽  
Guided Waves ◽  
Sandwich Panel ◽  
Sandwich Structures ◽  
Ultrasonic Guided Waves ◽  
Visualization Method ◽  
Honeycomb Core ◽  
Laser Ultrasonic ◽  
Honeycomb Sandwich ◽  
Ultrasonic Propagation

Abstract Honeycomb sandwich structures are widely used in aircraft owing to the superior characteristics, such as the light weight, the high specific bending stiffness and the high specific in-plane compressive strength. However the honeycomb sandwich structures are prone to have debonding damages at the interfaces between the skin and the honeycomb core, which degrades the mechanical properties largely. For inspection of damages in plate-like structures, the propagation of ultrasonic guided waves along the plate is effective. In this research, we attempted to detect the debonding at the skin/core interfaces in a honeycomb sandwich panel by using a laser ultrasonic visualization method. Debonding damages were artificially introduced in a sandwich panel consisting of two CFRP skin plates and an aluminum honeycomb core. Then, ultrasonic guided waves were excited in the panel through scanning of a laser irradiation on a surface of the plate and were received by a piezoelectric sensor installed on the same surface by using a laser ultrasonic visualizing inspector. As a result, we obtained visualization animations of the ultrasonic propagation behavior. From the change in the maximum amplitude distribution of the guided wave, we were able to identify the debonding damages at the skin/core interfaces in both the laser-irradiation side and the opposite side. Furthermore, a finite element analysis of the ultrasonic propagation in the honeycomb sandwich panel was conducted to confirm the phenomena observed in the experiments. From the calculation results, the mechanism of the observed phenomena was able to be clarified.

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.

Sound radiation and transmission loss characteristics of a honeycomb sandwich panel with composite facings: Effect of inherent material damping

2016 ◽  
Vol 383 ◽  
pp. 221-232 ◽  
Author(s):  
M.P. Arunkumar ◽  
M. Jagadeesh ◽  
Jeyaraj Pitchaimani ◽  
K.V. Gangadharan ◽  
M.C. Lenin Babu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Radiation ◽  
Material Damping ◽  
Honeycomb Sandwich

Dynamic Fracture Analysis of Aluminum Honeycomb Sandwich Panel

2006 ◽  
pp. 67-72
Author(s):  
Byung Il Kim ◽  
Byeong Wook Noh ◽  
Young Woo Choi ◽  
Sung In Bae ◽  
Jung Il Song
Keyword(s):  
Dynamic Fracture ◽  
Sandwich Panel ◽  
Fracture Analysis ◽  
Honeycomb Sandwich ◽  
Aluminum Honeycomb

An analytical model for the response of carbon/epoxy-aluminum honeycomb core sandwich structures under quasi-static indentation loading

2017 ◽  
Vol 21 (6) ◽  
pp. 1930-1952 ◽  
Author(s):  
Abhendra K Singh ◽  
Barry D Davidson ◽  
Alan T Zehnder ◽  
Benjamin PJ Hasseldine
Keyword(s):  
Analytical Model ◽  
Sandwich Structures ◽  
Plate Theory ◽  
Ritz Method ◽  
Design Tool ◽  
Face Sheet ◽  
Total System ◽  
Honeycomb Core ◽  
Static Indentation ◽  
Aluminum Honeycomb

An analytical model is developed to predict the loading and unloading response, as well as the residual dent diameter and dent depth, of carbon/epoxy-aluminum honeycomb core composite sandwich structures undergoing quasi-static indentation loading. The model considers damage created using spherical indenters and is valid up to the barely visible external damage threshold. The initial low load regime (until the onset of core crushing) is modeled using a combination of local Hertzian indentation of an elastic half-space and small deflection plate theory of a circular plate on an elastic foundation. For loads above those required to cause core crushing, the model uses the Rayleigh-Ritz method of energy minimization with the total system energy determined using a combination of face sheet bending energy, face sheet membrane energy and work done to the core during both elastic deformation and crushing. Degraded face sheet properties are used in the model beyond the onset of face sheet delamination, which is predicted using Griffith’s energy criterion. The model is validated using experimental results for sandwich structures consisting of quasi-isotropic 8- (thin) and 16- (thick) ply carbon/epoxy face sheets and aluminum honeycomb cores. The results show that the overall mechanics of the model are fundamentally correct and reflective of physical behavior. Thus, in its present form the model shows promise as a preliminary design tool.

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