Comparison of two‐ and three‐dimensional analyses of interface fracture data obtained from Brazilian disk specimens

Abstract

PurposeFracture tests carried out on bimaterial Brazilian disk specimens have been reported elsewhere. Two material pairs are tested in which each of the constituents is linearly elastic, isotropic, and homogeneous. For this material type, the crack fields decouple into in‐plane and out‐of‐plane deformation. Hence, a two‐dimensional approach is taken to analyse the tests. The purpose of this paper is to examine the necessity of using a three‐dimensional approach to predict interface fracture when in‐plane loading is applied.Design/methodology/approachTo this end, the specimens are analysed by means of two‐ and three‐dimensional finite elements. The interaction energy or M‐integral is used to calculate the stress intensity factors.FindingsThe paper shows that the Mode III stress intensity factor KIII is not negligible near the specimen outer surfaces. Nevertheless, a two‐dimensional analysis will be seen to be sufficient to analyse these tests. This has implications for the practical engineer.Originality/valueThe paper offers a comparison between two‐ and three‐dimensional fracture criteria for a crack along the interface between two homogeneous, isotropic, linear elastic materials when in‐plane loading is applied to the body, and assesses the importance of the out‐of‐plane deformation.