Determination of complex stress intensity factor for a crack in a bimaterial interface using digital image correlation

This paper addresses the problem of determination of the Stress Intensity Factor (SIF) for a crack in a bimaterial interface from the displacement fields obtained through Digital Image Correlation (DIC). Center cracked and edge cracked bimaterial specimens, as well as asymmetric 4-point bend specimens are tested and displacements are measured using DIC. Thereafter, the SIF is calculated by fitting the theoretical displacement field to the experimental data. The effect of the number of terms used in the theoretical displacement field on the SIF is discussed. Further, the measured SIFs are compared with those obtained from theoretical results and/or finite element computations.

► Determined SIF for a crack in a bimaterial interface from the displacement fields through DIC.
► Three geometries were used: central crack, edge crack, 4-point asymmetric bending.
► Theoretical displacement fields were fitted to the experimental data.
► SIF was determined by iteratively increasing the number of terms in the series solution.
► Experimentally determined SIF was compared with the results obtained from FE analysis.