On the Mechanics of Composite Sinusoidal Honeycomb Cores

2003 ◽  
Author(s):  
Pizhong Qiao ◽  
Jialai Wang ◽  
Guanyu Hu
Keyword(s):  
Honeycomb Cores

Study on ultrasonic vibration–assisted cutting of Nomex honeycomb cores

2019 ◽  
Vol 104 (1-4) ◽  
pp. 979-992 ◽  
Author(s):  
Di Kang ◽  
Ping Zou ◽  
Hao Wu ◽  
Jingwei Duan ◽  
Wenjie Wang
Keyword(s):  
Ultrasonic Vibration ◽  
Nomex Honeycomb ◽  
Honeycomb Cores

Bending response of carbon fiber composite sandwich beams with three dimensional honeycomb cores

2014 ◽  
Vol 108 ◽  
pp. 234-242 ◽  
Author(s):  
Jian Xiong ◽  
Li Ma ◽  
Ariel Stocchi ◽  
Jinshui Yang ◽  
Linzhi Wu ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Sandwich Beams ◽  
Carbon Fiber Composite ◽  
Composite Sandwich ◽  
Honeycomb Cores ◽  
Bending Response

High fidelity modeling tools for engine liner design and screening of advanced concepts

2021 ◽  
pp. 1475472X2110238
Author(s):  
Julian Winkler ◽  
Jeffrey M Mendoza ◽  
C Aaron Reimann ◽  
Kenji Homma ◽  
Jose S Alonso
Keyword(s):  
Aircraft Engine ◽  
High Fidelity ◽  
Treatment Area ◽  
Modeling Tools ◽  
Physical Constraints ◽  
Acoustic Performance ◽  
Acoustic Liner ◽  
Bias Flow ◽  
Honeycomb Cores ◽  
Acoustic Treatment

With aircraft engines trending toward ultra-high bypass ratios, resulting in lower fan pressure ratios, lower fan RPM, and therefore lower blade pass frequency, the aircraft engine liner design space has been dramatically altered. This result is also due to the associated reduction in both the available acoustic treatment area (axial extent) as well as thickness (liner depth). As a consequence, there is current need for novel acoustic liner technologies that are able to meet multiple physical constraints and simultaneously provide enhanced noise attenuation capabilities. In addition, recent advances in additive manufacturing have enabled the consideration of complex liner backing structures that would traditionally be limited to honeycomb cores. This paper provides an overview of engine liner modeling and a description of the key physical mechanisms, with some emphasis on the use of low to high-fidelity tools such as empirical models and commercially available software such as COMSOL, Actran, and PowerFLOW. It is shown that the higher fidelity tools are a critical enabler for the evaluation and construction of future complex liner structures. A systematic study is conducted to predict the acoustic performance of traditional single degree of freedom liners and comparisons are made to experimental data. The effects of grazing flow and bias flow are briefly addressed. Finally, a more advanced structure, a metamaterial, is modeled and the acoustic performance is discussed.

Ballistic Impact Response of Foam-Filled Sandwich Composites

2001 ◽  
Author(s):  
Uday K. Vaidya ◽  
Biju Mathew ◽  
Chad A. Ulven ◽  
Brent Sinn ◽  
Marian Velazquez
Keyword(s):  
Cost Effective ◽  
Impact Response ◽  
Sandwich Composites ◽  
High Velocity Impact ◽  
Honeycomb Core ◽  
Velocity Impact ◽  
Foam Filling ◽  
Foam Filled ◽  
Honeycomb Cores ◽  
The Cost

Abstract Sandwich composites find increasing use as flexural load bearing lightweight sub-elements rail / ground transportation and marine bodies. In recent year, alternatives to traditional foam and honeycomb cores are being sought. One such development includes filling the cells of the honeycomb core with foam. The increased surface area allows stress forces to dissipate over a larger area than that offered by the honeycomb alone. This allows for use of lowering the cost of the honeycomb cells, and thereby making the design extremely cost-effective. In the present research, phenolic impregnated honeycomb / corrugated cells with polyurethane foam filling has been considered. The intermediate and high velocity impact response of these types of sandwich constructions has been studied. The applications for such cores would be in rail and ground transportation, where impacts in the form of flying debris are common.

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.

Ballistic impact behaviors of aluminum alloy sandwich panels with honeycomb cores: An experimental study

2016 ◽  
Vol 20 (7) ◽  
pp. 861-884 ◽  
Author(s):  
QN Zhang ◽  
XW Zhang ◽  
GX Lu ◽  
D Ruan
Keyword(s):  
Aluminum Alloy ◽  
Energy Absorption ◽  
Impact Velocity ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Ballistic Limit ◽  
Core Density ◽  
Impact Tests ◽  
Honeycomb Cores

To study the protection property of aluminum alloy sandwich panels with honeycomb cores under the attack of bullets or debris, quasi-static perforation, and ballistic impact tests were conducted, in which the thicknesses of the face sheet and core were 0.5–2.0 and 12.7 mm, respectively, while projectiles with diameter 7.5 mm and impact velocity 50–220 m/s were employed. Based on the experiments, the influences of impact velocity, face sheet thickness, core density as well as the nose shape of the projectiles were investigated. The results showed that in the impact tests, the sandwich panels dissipated much more energy than those in quasi-static perforation tests, and the energy absorption and ballistic limit of the sandwich panels increased with the increase of impact velocity. The influence of face sheet thickness was more remarkable than the core density, which was due to the relative density of honeycomb is too small. Although the increase of core density could induce the increase of energy absorption, this effect is more effective for thinner face sheet. Moreover, under the same impact velocity about 200 m/s and face sheet thickness 1.0 mm, the ballistic limit for conical-nosed projectile is highest, while it is lowest for flat-nosed projectile.

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