A crack between two dissimilar media

The present paper deals with the assessment of strength of a structure with a crack located between two different elastic materials subjected to extensional and in-plane non-uniform loading. Some problems concerned with the complex exponent of the stress field, oscillatory singularity range near the crack tip and interpretation of stress intensity factors KI and KII are discussed. New modified stress intensity factors KI and KII are proposed and analytical formulae of the stress field components around the crack tip are given. Theoretical results of the stresses are compared to the numerical ones obtained by means of the boundary element method BEM. Normalised weight functions are also obtained which enable to determine numerical values of the stress intensity factors KI and KII for any normal and shear stresses released along the crack surfaces. Dugdale strip yield model is also extended to interfacial crack. Some particular solutions of the model are presented for various material constants and loading conditions. Crack opening displacement parameter based on the energy approach is also derived and discussed.