The deformation of foamed elastic materials

Abstract

Abstract A theoretical treatment is given which predicts the behavior of a foamed elastic material on the basis of a model consisting of a network of thin threads. Two cases are considered: ( 1 ) small strains, and ( 2 ) finite compressions, when the major part of the deformation of the threads is attributed to buckling. The behavior is given in terms of Young's modulus of the matrix and the density of the foam. Measurements of the load‐deformation relations for small tensile strains and finite compressions are described for natural rubber foams prepared from latex. A wide range of density is covered (0.09–0.57), giving a variation of compression hardness of about 100:1. Satisfactory agreement with theory is found for both the cases considered, indicating that the basic concepts of the structure and mode of deformation are correct.