Experimental and Numerical Investigation of V-Shaped Epoxy Adhesive Joints

This paper deals with the stress and failure characteristics of V-shaped epoxy adhesive joints. The effect of scarf angles upon failure morphology was investigated by tensile tests and monitoring using high speed cameras. V-shaped specimens were fabricated with three bond thicknesses, t (i.e. 0.2mm, 0.6mm, and 1.0mm) and various scarf angles (i.e. θ = 30˚, 45˚, 60˚, 75˚, and 90˚). From failure surface observation, failure morphology can be divided into five types, consisting of interface failure and/or cohesive failure. Shear stress plays a major role in failure morphology where higher shear stress favors interface failure in the specimens tested. A simple failure criterion is also proposed based on the results obtained. It is found that the proposed criterion can approximately predict the failure stress of V-shaped epoxy adhesive joint specimens. For stress analysis, V-shaped epoxy adhesive joints having bond thicknesses t = 1.0mm, and with various scarf angles (i.e. θ = 30˚, 45˚, 60˚, 75˚, and 90˚), were modelled. Stress singularity observed in simulation plays a major role in failure morphology where higher singularity favors cohesive failure in the specimens tested in experiment.