Vibration Behavior of Foam-Based Laminated Sandwich Beams Using a Modified Layerwise Theory

The vibration response of laminated sandwich beams, with a core layer filled with various foam materials, referred to as Foam-based Sandwich Laminated Composite (FSLC) beams, has been studied. First, to precisely capture the varying material properties across the thickness of the sandwich beams, a modified layerwise displacement theory was employed. This approach addresses the inhomogeneity of the foam material in the core, yielding more accurate results than conventional classical laminated plate theories typically used for analyzing laminated composite structures. Secondly, to assess the impact of foam properties on dynamic behavior, FSLC beams incorporating three distinct types of foam have been analyzed. Thirdly, a proof-of-concept experimental test was conducted to demonstrate the functionality of the proposed model under dynamic loading conditions. The natural frequencies and damping coefficients of the FSLC beams have been determined using the modified layerwise theory. The dynamic response of the FSLC beams under impulse loading has also been analyzed. It was observed that the addition of foam in the core layer enhances the damping properties of the sandwich beam by approximately ten percent while reducing the natural frequencies by approximately five percent under all types of loading considered.