Sandwich Construction: Correlation and Extension of Existing Theory of Flat Panels Subjected to Lengthwise Compression

An extensive bibliography exists on sandwich construction; it is felt, however, that few of the available papers are readily adaptable for use in aircraft design offices. This paper, whilst based on an existing theory, extends it to include panels with faces of unequal thicknesses and aeolotropic cores such as honeycomb. The various modes of failure are described, and comparisons are drawn between the equilibrium equations and those derived in the theory of solid plates. A very simple equation for the overall instability of a sandwich panel is obtained, based on the concept of ‘width reduction factors’ which make allowance for core flexibility and unequal face thicknesses. Methods are described for presenting these reduction factors' and other important parameters in the form of data sheets, of which examples are given. The panels which are discussed are assumed to be flat, and compressed by a load uniformly distributed across their ends. The edges, which are simply‐supported, are taken to be long in relation to the panel width.