Numerical and experimental response of FSSW of AA5052-H32/epoxy/AA5052-H32 sandwich sheets with varying core properties

摘要

Abstract The present work aims to assess the joint behaviour of friction stir spot welded sandwich sheets by changing the quality of the epoxy core layer. Lab scale experiments and numerical simulations are conducted for the purpose. The core property is altered by varying hardener to resin (h/r) ratio within a suitable range. Joint mechanical performance and joint characterization are evaluated from experiments. Cohesive zone modelling has been incorporated in Abaqus to monitor the hook formation and interface delamination, which is not performed until now in literature. The core quality influences the behaviour of sandwich sheet and hook geometry significantly. Desired h/r ratio is also evaluated from such results, and FSSW is found advantageous at some h/r ratios. The failure mode is independent of h/r ratio and loading conditions. The final joint shape and hook geometry obtained from FE simulations agree well with that of from experiments. Cohesive zone modelling helped in accurate prediction of delamination, and without it, the hook geometry and plastic energy dissipation predictions are approximated. It has been suggested to incorporate cohesive zone model during FE simulations to have a realistic prediction of sandwich joint performance.