Evaluation of dynamic fracture toughness of a bonded bi-material interface subject to high-strain-rate shearing using digital image correlation

The fracture toughness at the bi-material interface of layered test pieces is determined using digital image correlation (DIC) as part of dynamic shear tests. High-strain-rate shear tests are conducted on a three-layered bonded test piece comprising a central aluminum layer with PMMA resin layers. When the crack is sufficiently shorter than the bonding interface length, mode II fracture appears at the aluminum–PMMA interface; otherwise, mode I and mode II fractures appear. As the obtained stress intensity factor is consistent with the literature values, a reasonable interface fracture toughness can be evaluated using the DIC.