Tensile behavior of bonded scarf joints between composite adherends

Tensile tests of bonded scarf joints indicate that shallow angle joints are sensitive to slight adherend tip bluntness. For scarf angles ranging from 9.2 to 1.1 degrees stress concentrations from blunt adherend tips significantly limit the increased strength expected from larger bond area. The bonded joints fail by two failure modes depending on the scarf angle. Although most of the joints in this study were scarfed by a surface grinder, small angle scarfs can be cut very accurately with a hand held rotary bur.