Analytical and Experimental Study of Sandwich Beams with Flexible Core and Composite Facings Reinforced with Carbon Nanotubes

Today, sandwich structures are being used in many applications. Understanding the behavior of these structures and their properties is necessary for proper and optimum design. Because of thin face sheet and low stiffness of foam core, sandwich beams are very sensitive when exposed to local loading. Due to their structure, carbon nanotubes (CNT) have excellent mechanical properties, which improve the mechanical properties of the polymer when added to polymer matrix. In this article, the indentation behavior of sandwich structure is studied experimentally and theoretically. ABAQUS software is used for modeling the indentation behavior of sandwich beam. Elastic modulus of epoxy resin reinforced with CNT with different weight fractions is obtained with use of Mori-Tanaka theory and also by fabrication and testing of the composite specimens. Results show that adding CNT up to 0.3 %wt improve the elastic modulus of composite, while weight fraction of CNT more than 0.3% decrease the mechanical properties. Finally, the results obtained from the analytical solution and ABAQUS modeling were compared with the results obtained from experimental tests of indentation of sandwich structures. An acceptable agreement was observed between the results.