The incurved Brazilian disc as an alternative to the standardized Brazilian disc test

Abstract

A modified configuration of the standardized Brazilian disc is proposed here, namely the incurved Brazilian disc, aiming to address the main drawback of the traditional indirect tensile test introduced by Carneiro and Akazawa (broadly known as the Brazilian disc test), namely the onset of fracture from the disc-jaw contact region rather than from the center of the disc. In this context, the disc is circularly truncated in the vicinity of the disc-jaw contact area, leading, in fact, to a wide, and as it is seen predefined contact length. The wide extent of the contact arc ensures small stress concentrations, while its predefined length ensures independence of the outcomes of the tests from material and geometry. The incurved Brazilian disc is compressed between the flat loading platens with the aid of two semicircular indenters, which will completely fit into the cavities of the disc under load. The analytical solution of the described configuration is obtained using Muskhelishvili’s complex potentials method. Comparison of the results of the present analysis concerning the stress and displacement fields with the respective ones due to existing solutions for the traditional Brazilian disc as well as with those of the flattened Brazilian disc, reveals interesting aspects of the modified configuration proposed, enlightening some advantages, concerning mainly the intensity of the stress field in the disc-jaw contact area.