Bending behavior of low-cost sandwich plates

A simple sandwich plate theory, which is an extension of an existing sandwich beam theory, is presented. The solution for a sandwich plate simply supported along two opposite edges, free along the two other opposite edges, and loaded by a line load is developed with a superposition approach that has been used for classic isotropic plates. The construction of a low-cost sandwich plate using glass/PET facesheets and a nylon/PET core bonded together with a urethane adhesive is discussed. The experimental set-up to test the plate under the conditions assumed is described. Out-of-plane displacements using dial gage and shadow moiré measurements are compared with predictions of the theory. The lack of ideal simple supports and accurate facesheet mechanical properties results in a less than ideal correlation between predictions and measurements. However, these issues are accounted for and a satisfactory correlation is obtained.