Three-Point Bending Test and Experimental and Numerical Modal Testing of Sandwich Plates with Grid Stiffened Core

In the present study three composite sandwich structures with grid stiffened core (SSGSC) samples made of different materials and thicknesses are fabricated with hand lay-up method using a silicon rubber mold and epoxy resin. Also, two metallic samples of the same dimensions as the composite ones, including a monolithic and a SSGSC samples made of aluminum are fabricated. In order to study their behavior subjected to the quasi-static transverse loads, the samples undergo three-point bending tests. Results of the practical tests on the composite samples showed that beyond the failure of the face sheets, the grid stiffened core will tolerate load, also there are no delamination between the face sheet layers due to good curing process. The experimental modal testing is achieved on all the samples. The frequency response, mode shape as well as damping coefficients are obtained from each experiment. Finally, numerical modal analysis is done and the results are compared with the experiments.