Failure of adhesively bonded metallic T-joints subjected to quasi-static and crash loading

• Testing of adhesive structures.
• Rate- and loading direction dependent behaviour.
• Influence of manufacturing.

Experimental studies on adhesively bonded metallic joints are presented. The T-joints were mounted in a servo-hydraulic machine and loaded in three different directions (rear, front and side) and at three different loading velocities (0.5 mm/s, 50 mm/s and 5000 mm/s). The variation in loading direction allowed triggering of different failure mechanisms: metal plasticity, peel failure of the adhesive, shear failure of the adhesive and combined failure. Some scatter was seen in the joint performance which can be attributed to two major manufacturing parameters. The use of glass spheres for defining the bond line thickness has a positive effect on joint performance. Interestingly, T-joints manufactured from two different batches of adhesive showed large differences in behaviour although the manufacturing parameters were the exactly same.