Critical thrust force predicting modeling for delamination-free drilling of metal-FRP stacks

The aim of this paper is to study about delamination during drilling metal-FRP (Fiber Reinforced Polymer Composite) stacks, with the effect of the metal part taken into account. Two cases were studied, case (a): drilling form metal to FRP and case (b): drilling form FRP to metal. In case (a), a mechanical model for predicting the critical thrust force (CTF) was established based on linear elastic fracture mechanics, classical bending plate theory and the mechanics of composites. In case (b), plate shape and edge conditions were taken into consideration to analyze the deformation of the metal plate. The superposition principle was applied to calculate the effect of the deformation of the metal plate and FRP plate on the CTF, and a mechanical model was established based on the analysis in case (a). A series of experiments have been performed and the rationality of the models was testified.