Fabrication, Experimental Modal Testing, and a Numerical Analysis of Composite Sandwich Structures with a Grid-Stiffened Core

Composite sandwich structures with a grid-stiffened core (SSGSC) are one of the new structural configurations employed in advanced industries, and therefore the knowledge of their dynamic characteristics is very important. Hence, in the present study, three composite SSGSC samples of glass/epoxy and carbon/epoxy were fabricated by the hand lay-up method using a silicon rubber die. Also, two metallic samples — a monolithic one and a SSGSC, made of Aluminum 1050, were fabricated. The core of the aluminum SSGSC was produced using the wire cutting process, and the face sheets were attached using a high-grade adhesive. Modal experiments were carried out on all the samples using B&K vibration equipment. The frequency, mode shape, and damping coefficients were obtained from each experiment. Finally, a numerical modal analysis was performed, and good agreement between experimental and numerical results was obtained.