The perforation resistance of glass fibre reinforced PEKK composites

This paper presents a study focusing on the perforation resistance of glass fibre-reinforced PEKK composites. Woven S-glass fibre (GF) reinforced poly-ether-ketone-ketone (PEKK) thermoplastic prepreg materials were manufactured using a dry powder prepregging method. Prior to impact testing and modelling, the properties of the composites were evaluated by conducting a series of quasi-static tests at room and elevated temperatures. Quasi-static tensile and perforation tests showed that the optimum weight fraction of PEKK, w_f, is approximately 0.4, which gives the peak tensile strength and perforation resistance. Tests at elevated temperatures highlighted the excellent stability of these materials under extreme conditions. As expected, the energy required to perforate the targets increased with projectile diameter. Subsequent tests highlighted the severity of conically-shaped projectiles with the perforation resistance dropping under sharp object impact loading. A series of finite element models were also developed to predict the response of the glass fibre/PEKK composites to impact by projectiles based on different diameters and shapes. The predictions were validated against the experimental force-displacement traces and failure modes with good agreement.