Elastic Stiffness Properties and Behavior of Truss-Core Sandwich Panel

Abstract

In this paper, a truss-core sandwich panel is introduced and its elastic properties are presented. Two thin flat sheets, separated by two inclined plates acting as the core and rigidly jointed at their ends, characterize the sandwich section. This construction form eliminates most of the attendant problems of conventional spot-welded or rivet-fastened sandwich panel construction. Advantages of the truss-core panel are discussed. The 3D sandwich panel is idealized as an equivalent 2D orthotropic thick plate continuum. Equivalent bending, twisting, and transverse shear stiffness are derived, and the influence of the relatively weak shear stiffness on the behavior is discussed. By integrating these elastic stiffness constants into closed-form solution, panel response is calculated. The calculated results, which require significantly less computational effort, agree well with 3D finite-element analysis. Comparisons of stiffnesses and deflections with the corresponding responses of conventional sandwich construction are provided. This study indicates that the truss-core sandwich panel performs better due to its inherently higher flexural resistance per unit weight.