FRACTURE-ANALYSIS OF BONDED ELASTOMERIC DISKS SUBJECTED TO TRIAXIAL STRESS

A theoretical model for the dependence of the modulus of elasticity, M , on the porosity, alpha, of an elastomeric disk subjected to triaxial stress was developed. An empirical law was proposed for the dependenc e of the surface energy, Gamma, on the porosity, alpha, of the elastom er. The presented theoretical model is a two-degree-of-freedom model, the parameters of which are determined by fitting with experimental da ta derived from the elastomer disks. In order to obtain the final math ematical expression for the effective modules of the composite system, a relationship between the strain field within the disk and the poros ity was developed. The numerical differentiation of the experimental s tress/strain curve from the tested bonded elastomer disks yields the v alues of the apparent modulus of the elastomer disks as a function of the strain field within the testing specimens. An appropriate combinat ion of the proposed theory and the received experimental data yields t he percentage of the growing microvoids within the deformed material. (C) 1997 John Wiley & Sons, Inc.