The load-deflection behavior of a US Army Corps of Engineers available sandwich plates in three-point bending with glass phenolic facings and balsa wood core is being investigated under room and elevated temperatures. Test data on bending rigidity, critical interfacial failure (skin-to-core interface) and shear stress are collected and analyzed. The load-deflection curves plots up to the point of failure initiation are being studied. The effects of the span and the radius of the loading nose on the bending modulus and strength are examined systematically. Theoretical calculations from a modified beam theory of sandwich structure are applied and the effect of the shearing rigidity of the core is studied, and the propensity with respect to the span is also investigated. A finite element model is developed to study the flexural and stress analysis. Based on the results, this thesis proposes a desirable analytical approach that correlates theory with experiment as defined below.