
Accession Number : AD0606858
Title : POISSON'S RATIO FOR HONEYCOMB SANDWICH CORES,
Corporate Author : RAND CORP SANTA MONICA CALIF
Personal Author(s) : Hoffman,George A.
Report Date : 07 APR 1958
Pagination or Media Count : 6
Abstract : An interesting mechanical property of honeycomb cores is their Poisson's ratio: it is very sensitive to cell geometry and can assume values from zero to about three. Large values may be observed when flexing some slabs of honeycomb with flat cell walls, while rippled wall honeycombs demonstrate zero Poisson's ratio. The ratio of anticlastic curvatures is indicative of the value of Poisson's ratio for axial loading in the plane of the slab. Equilateral hexagonal and square cells were considered here; the doubled foil line the xdirection, and the cell width, a, the spacing between doubled foil lines (see insert, Fig. 1). The angle d between the xaxis and an adjacent wall is 60 degrees for regular hexagonal cells, though in practice it may be much less (the socalled underexpanded core), or well beyond 60 degrees overexpanded cores). Reducing the doubled foil line to a minimum, results in a nearly quadrilateral cell, herein assumed square. Conforming to common practice, the doubled foil line was assumed parallel or perpendicular to the loading or bend axis.
Descriptors : (*HONEYCOMB CORES, ELASTIC PROPERTIES), (*ELASTIC PROPERTIES, HONEYCOMB CORES), SANDWICH CONSTRUCTION, STRUCTURAL PROPERTIES, STRAIN (MECHANICS), STRESSES, MATHEMATICAL ANALYSIS, INTEGRALS
Distribution Statement : APPROVED FOR PUBLIC RELEASE