Experimental investigation of the effect of key variables on the static strength of aluminum alloy structural adhesive joints

Fuel economy targets are pushing car makers to develop several strategies in order to reduce the weight of the vehicles. Within this scenario adhesive bonding is nowadays a widespread technology that represents a joining technique aiming to replace or to combine fastening for lightweight construction of car bodies and multi-material design. In this work an experimental investigation into the static strength of aluminum alloy structural adhesive lap joints is carried out by varying factors influencing the bonding behaviour of the joint. The impact of surface roughness, geometrical control factors (adherend thickness and adhesive thickness) and test conditions (test temperature and test speed) is evaluated. The outcomes derived from the tensile tests are analyzed in terms of load, elongation and energy at failure. Finally a failure mode analysis is conducted in order to either verify or explain the results obtained.