Design, fabrication and properties of sandwich composites with metamaterial absorbers integrated

Abstract

In order to achieve a kind of composite material with both wave absorbing property and certain mechanical load bearing function, the metamaterial absorbers and sandwich composite were combined. By simulation, the metamaterial absorbers satisfying dual-band and broadband electromagnetic wave absorption were designed, and the wave absorbing performances were characterized. The aforementioned metamaterial absorbers were then integrated into the sandwich composite, in which the glass fiber/epoxy composite was used as the top layer, the PMI foam was used as the core layer, and the carbon fiber/epoxy composite was used as the bottom layer. The measured electromagnetic wave absorbing performance of the final sandwich composites shows that the dual-band composite has the absorptivity of 94.13% and 99.99% at the frequency of 8.65 GHz and 10.30 GHz respectively，while the broadband composite has the absorptivity of 90.02%-99.91% at 8.25-11.61 GHz frequency range. The bending test results exhibit that the dual-band composite has the bending strength and modulus of 68.81 MPa and 7.72 GPa， and the broadband composite has the bending strength of 145.76 MPa and modulus of 9.13 GPa. The SEM photos of after-fracture cross sections show that a small area of delamination can be observed and the overall laminates bonding performance is good.

Keywords

• metamaterials
• composite materials
• structural design
• wave absorbing performance
• bending properties