Mechanical Behavior of a Ceramic Sandwich Composite System

Abstract

The mechanical behavior of a ceramic sandwich composite system was in vestigated. The system was comprised of a low density, cellular Al₂O₃ core, bonded to dense Al₂O₃ faceplates. Tensile faceplate stresses during flexure were determined for a va riety of face thicknesses and core densities using a strain gage technique. For most com posites, the data agreed well with simple sandwich theory. For composites with relatively thick faces and low modulus cores, however, localized bending caused higher than ex pected face stresses beneath the load point. These stresses were predicted using a refined model. The strain gage data were also used to measure sandwich stiffness, which were well predicted by conventional sandwich theory when localized face bending was not prevalent. The structures were linear elastic to failure, though the failure was noncata strophic. For the sandwich geometries studied, failure initiated exclusively in the core.