Moiré Interferometric Analysis of Crack Nucleation From Bimaterial Corners

Bimaterial corners arise in many modem structural components from structural adhesively bonded joints to line structures in microelectronics devices. The elasticity problem has been extensively analyzed (Williams, 1952, Bogy, 1971, Hein and Erdogan, 1971) and it has been shown that singularities in stress can arise, depending on the properties of the materials and the corner geometry. These singularities (or eigenvalues) may be complex in nature and a number of them may co-exist for a particular configuration. Various schemes have been developed for extracting the stress intensity factors (or eigenvectors) associated with each singular term (Stem et al, 1976, Carpenter and Byers, 1987).