Damping of Hybrid-Weave Composite Laminates

Carbon fiber reinforced polymer composites have seen increasing use in aerospace vehicles as a means to reduce weight and improve performance. The large amount of design variations available to composite structures also allows for detailed tailoring of the structure on scales ranging from the intralaminar to full laminate. Continued research is needed to better understand the effects of these variations on structural stability and reliability. The ability of the material to dissipate vibration, i.e. damping, is often related with structural reliability, especially for structures subjected to sustained dynamic loading. Consequently, the effect of interleaving fibers of different material on the damping of laminate composites is the focus of this paper. Braided fiber laminate panels including all-carbon, 50/50 carbon/aramid, and 50/50 carbon/glass blends were subjected to vibration and sound radiation testing. Results showed the hybrid laminate panels to possess inherently higher damping, especially the carbon/aramid laminate with ~2.5 times higher damping relative to the all-carbon laminate. While other aspects including weight and material strength need to be considered, choice of hybrid material laminates may provide a beneficial trade for applications requiring higher structural damping.