Effect of various weaving architectures on mechanical, vibration and acoustic behavior of Kevlar-Hemp intra-ply hybrid composites

Due to the benefits of including high stiffness, low density, low cost, ecologically benign nature and abundant availability, natural fibers are employed as reinforcement in composites. These fibers however have a few shortcomings, including poor moisture resistance and incompatibility with most matrices. Therefore, the goal of this research is to combine the benefits of natural fiber (hemp) with synthetic fiber (kevlar) to develop a hybrid composite. Hemp and Kevlar yarns were handloomed to form fabrics with different architectures such as plain, twill and basket. These hybrid fiber epoxy composites were fabricated using compression molding and the samples were subjected to mechanical testing, free vibration and acoustic emission characteristics. Hemp and Kevlar fiber composites were also fabricated for comparison purpose. The results revealed that the twill and basket weave intra ply hybrid composites exhibited the better mechanical properties when compared with the plain weave hybrids. Whereas, the free vibration results showed that the all the hybrids exhibited better performance that the mono-fiber composites. Acoustic behavior of the basket weave hybrid was found to have the highest sound transmission loss value of 13.7 dB in the higher frequency range. On the other hand, the hempepoxy composites exhibited the highest sound transmission level of 6.3 dB in the lower frequency range.