Strength and fracture characteristics of shear adhesive dissimilar joint

Abstract

In this study, the effect of bond thickness upon the shear strength of epoxy adhesively bonded joint with dissimilar adherends is addressed. The bond thickness, t between the adherends is controlled to be ranged from 0.1 mm to 1.2 mm. Finite element analyses are also executed by ANSYS 11 code to investigate the stress distributions withiin the adhesive layer of adhesive joint. As a result, shear strength of adhesive joint reduces with increasing bond thickness. The strength of shear adhesive joint is also dependent on elastic modulus of adherend. Moreover, the failure of dissimilar adherends bonded shear joint originated at a location with critical stress-y which is the interface corner of ALYH75/epoxy. In the case of shear adhesive joint with an interface crack, the fracture also occurred at the ALYH75/epoxy interface even in the SEA specimens. Fracture toughness, Jc of AES is close to those of SES and demonstrates strong dependency upon bond thickness. Furthermore, the interface crack in SEA specimen has relatively large fracture resistance if compared to those in AES specimen. Finally, Kc fracture criterion is found to be appropriate for shear adhesive joints which fracture adhesively.