Deformations of Foamed Elastomers

Abstract

Geometrical shapes of interstices of two types of closest packing of uniform spheres, 1) hexagonal closest packing, 2) face centered cubic closest packing are studied, and the structures of interstices of these two types of packing are used to represent those of the actual foamed elastomers.

Equivalent elastic constants for these two structures are calculated in terms of the slenderness of a thread (which is a function of voids content) l'/A where l is the length of a thread and A its cross-sectional area, and of the elastic constants of the interstices. The calculated value of Poisson's ratio of a model containing 67 percent of the interstices of hexagonal closest packing and 33 percent those of face centered cubic packing corre lates fairly well with existing experimental data.

Get full access to this article

View all access options for this article.

References

P. J. Blatz and W.L. Ko , Trans. Soc. Rheo . 6, 223 (1962).

A. N. Gent and A.G. Thomas , J. App. Poly. Sci ., 1, 107 (1959).

J.A. Talalay , Indus. and Eng. Chem., 46, No. 7, 1530, July (1954).

T.L. Smith , "Elastomeric-Binder and Mechanical Property Requirements for Solid Propellants. Memo. No. 20-178, Jet Propulsion Laboratory , January (1959).

T.L. Smith , Trans. Soc. Rheo., 3, 113 (1959).

Z. Hashin (Haifa) , The Moduli of an Elastic Solid Containing Spherical Particles of Another Elastic Material. Non-Homogeneity in Elasticity and Plasticity (International Union of Theoretical and Ataplied Mechanics). W. Olszak, Pergamon Press, New York, 463-478 (1958).

D. Hilbert and S. Cohn-Vossen , Geometry and the linagination. Chelsea Pub. Co., New York (1952).

G. Horvay , J. App. Mech., 19, 355 (1952)

M. Gardner , Scientific American, 202 , 174, May (1960).