Modelling the effect of projectile hardness on the impact response of a woven carbon-fibre reinforced thermoplastic-matrix composite

Abstract In the present paper numerical modelling results are described to predict the effects of the hardness of a projectile impacting a woven carbon-fibre reinforced thermoplastic-matrix composite. The projectiles are prepared from either relatively soft gelatine or hard high-density polyethylene (HDPE) materials, of the same mass, and are fired from a gas-gun at about 60 m.s-1 to impact a woven carbon-fibre reinforced poly(ether-ether ketone) (woven CF/PEEK) composite. A two-dimensional, elastic, finite-element analysis (FEA) model is developed to simulate the gas-gun impact experiments and study the impact damage processes, and this numerical model is relatively computationally efficient. This FEA model makes predictions for the plastic flow for the gelatine projectile and the elastic deformation of the polyethylene projectile. In addition, the model predicts the effects of the hardness of the projectile on (a) the deformation of the impacted composite specimens and (b) the location and extent of damage in the composites. Very good agreement between the predictions from the model and the experimental measurements is observed. This research is of key importance in studying the behaviour of thermoplastic-matrix composites under impact loading by various types of threat such as relatively soft bodies, e.g. birds and hard objects, e.g. dropped-tools and runway debris.