Strength and failure mode of adhesively-bonded joints at different loading rates

The time-dependent behaviour of adhesively-bonded double-lap joints has been tested. The adhesive used was FM300. Three different materials were used for the adherend, namely, carbon fibre reinforced composite with quasi-isotropic lay-up, aluminium and steel. The specimens were pulled at different speeds and the strength of the joints and failure patterns were recorded and analysed. The effect of different ratios of overlap length vs. adherend thickness was tested. The results indicate that in the room temperature-dry environment for reasonably long joints, the effect of pulling speed on the strength of the joints is negligible. In the hot-wet environment this effect becomes significant for the composite specimens tested.