A CONSTITUTIVE RELATIONSHIP FOR GELS UNDER LARGE COMPRESSIVE DEFORMATION

A three-parameter constitutive relationship was developed based on a strain energy function to describe the mechanical behaviour of gels subjected to large I deformation under compressive load. The parameters in the relationship can be estimated from experimental data using regression techniques. Alternatively, these unknowns may be determined directly from three compression parameters sigma(m), epsilon(m), beta, which represent the strength, ductility and nonlinearity of the mechanical behaviour, respectively. The new constitutive relationship fits experimental data, for both brittle and ductile gels, up to the point of compressive failure.