Enhanced mechanical and radar absorbing properties of carbon/glass fiber hybrid composites with unique 3D orthogonal structure

This paper investigates the benefits of 3D orthogonal architectures over laminated orthogonal composites in mechanical and radar absorbing properties. Tensile, short beam shear and flexural properties showed that the tensile strength, breaking elongation, bending strength, bending modulus and shear strength of the 3D orthogonal composite were 5%, 20%, 3%, 10% and 4% higher than those of the laminated orthogonal composite, respectively. Microscopy showed that the 3D orthogonal composite inhibited crack propagation in the interlayer due to the binding of Z-binder yarns. Free space measurements for radar absorption were conducted. The reflection loss of the 3D orthogonal composite was higher than that of the laminated orthogonal composite over 8-18 GHz bandwidth. Also, the EM wave absorption of the 3D orthogonal composite was more than 90% (below −10 dB) over 11.2-18 GHz waveband. Therefore, the 3D orthogonal composite offers a unique architectural method of attaining both outstanding radar absorption in the 11.2-18 GHz waveband and concomitant mechanical performance.