A Novel Approach to Enhance Mechanical Characteristics of Sandwich Composites

Sandwich composites find extensive applications in various fields like transportation, marine, aerospace and construction owing to excellent properties like high strength-weight ratio, bending stiffness, corrosion resistance, good energy absorption and acoustic characteristics. However, sandwich structures are susceptible to failures like de-bonding of skin and core, core shear failure, buckling etc. In the present work, an attempt is made to improve the mechanical performance of sandwich composites such as flexural strength, delamination resistance and shear strength by adopting a novel approach which is a combination of core and matrix modifications. Three types of sandwich composites were manufactured by vacuum infusion process: sandwich composites with (i) no modification (ii) core modification (iii) core and matrix modifications. Flexural, compression and shear tests were carried out on the manufactured specimens according to American Society for Testing Materials (ASTM) standards. The sandwich specimen with core modification showed better resistance to de-bonding and resulted in 20.83% increase in compressive strength compared to specimen with no modification. Sandwich composites with core and matrix modifications exhibited 11.44% increase in flexural strength and were able to withstand 38.84% more shear load compared to sandwich composites with no modification.