Adhesive bonding has been used as a joining technique for many years but its popularity has increased in the last two decades, however the ability to predict failure of bonded joints remains a difficult problem. Therefore, instead of using conventional approaches, predictive models like cohesive zone models (CZM) are now being used.
The accuracy of various beam theories for fracture toughness has been evaluated using the CZM approach and calibrated against experimental data obtained for a tapered double cantilever beam (TDCB) specimen. After obtaining some conclusive results, focus shifted towards the T-peel specimens and detailed parametric studies were conducted.
It was seen that TDCB is generally insensitive to the shape of the CZ law and only dependent upon fracture energy, a bi-linear CZ worked well in calibrating the specimen. The T-peel specimen gave inconsistent results when compared to Pirondi's work. However it is not appropriate to state conclusively that this is due to the change in shape of the CZ law, this needs to be further evaluated.