Abstract
In this study, fracture characteristics of epoxy adhesively bonded butt-joint of dissimilar metals,namely SUS 304 stainless steel and YH75 aluminium alloy were examined on various adhesive bondthicknesses in associations with artificial interface crack subjected to pure mode I loading.Finite element analysis was also executed to investigate the stresses distribution in adhesive layer and also evaluating fracture toughness of adhesive joints by ANSYS 11 code.The results show that the strength of adhesive joints without crack decreased with increasing bond thickness.The interface corner toughnessHc can be applied for predicting the strength of joints provided that any non-linear or fractureprocess zone is fully embedded within the region of singular elastic H-field.Interfacial crack in adhesive joints propagates in two directions, that is, along the interface (i.e. interface failure) or deviatedin to adhesive layer (i.e. cohesive failure).Next, the evaluated fracture toughness Jc of adhesive joints with interfacial crack was independent of bond thickness when failure was associated with crack deviated into adhesivelayer.Nevertheless, Jc for adhesive joints with interfacial crack was dependent on bond thickness when the failure was apparently interfacial.However, if the interfacial crack is analogous to the center crack in adhesive layer constrained between two rigid substrates, Kc parameter can be used to asses the fracture toughness of adhesive joints with interfacial failure.
