Internal Crack Symmetry Phenomena during Gas-Induced Rupture of Elastomers

Abstract

Abstract This paper describes an experimental and analytical investigation of the consequences of removing a high ambient gas pressure environment from a number of elastomers after they had been allowed to equilibrate under high gas pressure. The elastomers are irreversibly damaged, and the phenomenology of this damage is described. One particular type of damage, the formation of internal symmetrical cracks whose geometry is the same as that of the sample, is examined in detail. The experimental data are interpreted using two models. The first provides a first order, but somewhat artificial, description of the phenomenon observed. A more sophisticated model invokes two separate processes as the origin of the rupture phenomenon. It is argued that ruptures arise as a result of the combined effects of an overall hydrostatic tension and a localized tensile field which is created by the effusion of gas from the polymer. The severity of the latter is shown to be a function of the gas transport properties of the elastomer under the conditions which prevail during the gas desorption process.