This paper presents approximate closed-form expressions for the local
energy release rate in Mode I, Mode II, and Mode III along the idealiz
ed straight crack front of a cracked generalized adhesive joint. The d
evelopment is based on beam theory, the J-integral, and a beam-on-an-e
lastic-foundation model. Fracture experiments were performed with adhe
sively bonded split-cantilever-beam (SCB) specimens of different adher
end widths and thickness ratios using two different adhesives, and it
was seen that the fracture surface had a peculiar stepped arrowhead sh
ape. The analysis and the experiments showed that both the energy rele
ase rate and the mode mix vary along the crack front of an SCB specime
n, making it unsuitable for the determination of fundamental fracture
properties. However, the SCB specimen provided a useful means to test
an engineering approach to predict the out-of-plane fracture loads of
adhesive joints.