Microwave Absorbing Properties of Radar Absorbing Structure Composites Filling with Carbon Nanotubes

2011 ◽  
Vol 328-330 ◽  
pp. 1109-1112 ◽  
Author(s):  
Zheng Quan Zhang ◽  
Li Ge Wang ◽  
En Ze Wang
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Wave ◽  
Carbon Fibers ◽  
Electromagnetic Waves ◽  
Glass Fibers ◽  
Network Analyzer ◽  
Microwave Absorbing Properties ◽  
Radar Absorbing Structure ◽  
Lossy Materials ◽  
Wave Properties

Radar absorbing structures (RAS) can’t only load bearing but also absorb electromagnetic wave energy by inducing dielectric loss and minimizing reflected electromagnetic waves. Therefore, the development of the RAS haves become important to reduce RCS of the object. These composites possess excellent specific stiffness and strength. The electromagnetic wave properties of RAS can be effectively tailored by controlling the content of the lossy materials. Radar absorbing structures composed of glass fibers, carbon fibers and epoxy resin filling with carbon nanotubes (CNTs), was designed and prepared. Permittivity of the composite was measured by using a network analyzer, HP8510B. The contents of composites were observed to be different from each composite. Reflection of electromagnetic waves energy of RAS was calculated by using the genetic algorithm, it was discovered that the composites can be applied to design an optional RAS composites filling with CNTs.

High performance electromagnetic wave absorbers derived from PC/SAN blends containing multiwall carbon nanotubes and Fe3O4 decorated onto graphene oxide sheets

RSC Advances ◽  
2016 ◽  
Vol 6 (44) ◽  
pp. 37633-37645 ◽  
Author(s):  
Shital Patangrao Pawar ◽  
Mounika Gandi ◽  
Suryasarathi Bose
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Electromagnetic Wave ◽  
High Performance ◽  
High Surface ◽  
Multiwall Carbon Nanotubes ◽  
Attenuation Constant ◽  
Lossy Materials ◽  
Multiwall Carbon ◽  
Graphene Oxide Sheets

A high performance electromagnetic wave absorber with high surface resistivity and enhanced attenuation constant was designed using uneven distribution of lossy materials in PC/SAN blends.

Investigation on the flexural response of multiscale anisogrid composite panels reinforced with carbon fibers and multi-walled carbon nanotubes

2017 ◽  
Vol 52 (2) ◽  
pp. 225-233 ◽  
Author(s):  
Reza Eslami-Farsani ◽  
Alireza Shahrabi-Farahani
Keyword(s):  
Carbon Nanotubes ◽  
Energy Absorption ◽  
Carbon Fibers ◽  
Composite Structures ◽  
Glass Fibers ◽  
Bending Test ◽  
Composite Panels ◽  
Flexural Response ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Grid stiffened composite structures have been maturely developed in aircraft and automobile industries due to their excellence properties such as high specific strength, high specific stiffness, excellent energy absorption capability and corrosion resistance. In the current investigation, the effect of multi-walled carbon nanotubes addition in various weight percentages (0, 0.1, 0.25 and 0.4) on the flexural response of anisogrid composite panels was evaluated. For fabrication of the composite specimens, hand lay-up method was used where plain weave E-glass fibers and unidirectional carbon fibers impregnated to the epoxy resin that modified with multi-walled carbon nanotubes were used in the skin and rib parts, respectively. Experimental results from three-point bending test showed that with the addition of 0.4 wt.% of multi-walled carbon nanotubes, the maximum flexural load, flexural stiffness and energy absorption of anisogrid composite panels increased by 24%, 35% and 25%, respectively. Microscopic analyses revealed that the improvement in the flexural properties of anisogrid composite panels with the addition of multi-walled carbon nanotubes was due to improvement in the interfacial properties of matrix and fibers.

Microwave Absorbing Properties of Carbon Fibers Modified with BN/SiC Composite Coatings

2014 ◽  
Vol 29 (10) ◽  
pp. 1093 ◽  
Author(s):  
ZHOU Wei ◽  
XIAO Peng ◽  
LI Yang ◽  
LUO Heng ◽  
HONG Wen
Keyword(s):  
Carbon Fibers ◽  
Composite Coatings ◽  
Microwave Absorbing Properties ◽  
Microwave Absorbing

Detection of delamination in composites by using electromagnetic penetrating radar

2014 ◽  
Vol 5 (2) ◽  
pp. 151-156
Author(s):  
Z. Mechbal ◽  
A. Khamlichi
Keyword(s):  
Electromagnetic Wave ◽  
Electromagnetic Waves ◽  
Electromagnetic Wave Propagation ◽  
Wave Reflection ◽  
Image Features ◽  
Partial Reflection ◽  
Straight Path ◽  
Reflected Signal ◽  
Short Time ◽  
Intervening Factors

Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.

New Approach to the Theory of Circular Dichroism

1998 ◽  
Vol 63 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Jaroslav Zamastil ◽  
Lubomír Skála ◽  
Petr Pančoška ◽  
Oldřich Bílek
Keyword(s):  
Electromagnetic Wave ◽  
Circular Dichroism ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Optically Active ◽  
Semiclassical Approach ◽  
New Approach ◽  
Isotropic Media ◽  
New Formula ◽  
Circular Dichroïsm

Using the semiclassical approach for the description of the propagation of the electromagnetic waves in optically active isotropic media we derive a new formula for the circular dichroism parameter. The theory is based on the idea of the time damped electromagnetic wave interacting with the molecules of the sample. In this theory, the Lambert-Beer law need not be taken as an empirical law, however, it follows naturally from the requirement that the electromagnetic wave obeys the Maxwell equations.

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