Investigating damping properties of nanocomposites and sandwich structures with nanocomposites as core materials

This research aims to investigate the damping responses of the epoxy-based nanocomposites as well as the composite sandwich structures with the nanocomposite as core materials. Both the silica nanoparticles and the rubber particles (CSR, CTBN) were introduced in the epoxy matrix through the sonication process to form the nanocomposites. Furthermore, the nanocomposites were sandwiched between the unidirectional composites laminates to fabricate the nanocomposite sandwich structures. The damping performances of the nanocomposites as well as their sandwich structures were determined from the forced vibration technique together with the half-power method. Meanwhile, the flexural stiffness of the material systems was evaluated by the resonance frequency obtained from the vibration tests. Results indicated that either silica nanoparticles or rubber particles can improve the damping responses of the epoxy-based nanocomposites. However, it was found that when the rubber particles were present alone, the stiffness of the nanocomposites was dramatically reduced. By introducing the hybrid material systems (10 wt% silica nanoparticles and 10 wt% rubber particles), the superior damping properties and flexural stiffness can be concurrently accomplished. Moreover, when the hybrid material system was employed as core materials in the sandwich structures, this enhanced damping property can also be observed in the vibration tests.