Design of carbon/glass/epoxy-based radar absorbing composites: Microwaves attenuation properties



Due to high specific strength, fatigue resistance, and stiffness, reinforced plastic composites have great deal of relevance in aerospace applications such as electromagnetic interference shielding, radar absorption, etc. These radar absorption structures offer good mechanical properties, absorption characteristics, and less interference with external profile making them viable for aerospace structure design. Present venture trades the investigation concerning the attenuation of electrical component (electromagnetic waves) through the inclusion of different carbon-based absorbers in glass/epoxy. Short carbon fibers like carbon black and multi-walled carbon nanotubes were utilized as the lossy components. The samples were manufactured via vacuum assisted resin infusion technique which gave uniform thickness and minimum void content. Particles were mixed in resin and infused in the glass preform. The effects of changing the absorber materials, number of layers of glass fiber mat and glass fiber itself were analyzed. Sandwiched absorbing structures with aramid honeycomb were also fabricated. The samples were tested via free space measurement technique. Two charts of results were obtained i.e. one with dielectric parameters and other with the reflection loss. Short carbon fibers showed the best fallouts in this study. Moreover, thickness with 16 layers of glass fiber was also evidenced as optimum for the structure. POLYM. ENG. SCI., 54:2508–2514, 2014. © 2013 Society of Plastics Engineers