Experimental Study of Self-Similar Crack Distributions

Abstract

This paper presents laboratory experiments on polyester resin samples subjected to special regimes of curing under which multiple shrinkage cracks with wide distributions of sizes were produced. Loading these samples produced stress-strain curves that followed a power law within certain stress ranges. The results of the tests were analysed using the mechanics of materials with self-similar crack distributions. The analysis showed that the observed power law in the stress-strain relationship indicated that the crack distribution was approximately self-similar. Thus, the described experiments serve as a verification procedure for the proposed formation mechanism of multiscale self-similar crack distribution in brittle materials. This mechanism is based on: (1) the action of self-equilibrating stress fluctuations as initiators and propagators of cracks and (2) the size discriminating action of crack interaction. The concentration factors for the crack distributions have been retrieved from the experimental data.