The Role of Adhesive in the Load Response of Adhesively Bonded Aluminum Hat Sections Under Axial Compression

Aluminum hat section, either adhesively bonded or unbonded, experiences buckling, post buckling and plastic collapse when axially compressed. However, there exist obvious differences in the load response between the bonded and unbonded hat sections. Finite element eigenvalue buckling analysis is carried out to predict the buckling load and mode. Experiments show that when adhesively bonded hat sections begin to buckle there is a transformation from the first buckling mode to the higher ones, while the unbonded hat sections develop the post buckling based on the lowest buckling mode. The different buckling modes result in not only different buckling loads but different peak loads of the hat sections as well. Finally, the ultimate compressive strength formulae are proposed for the hat sections.