Effects of high-speed impacts on CFRP plates for space applications

In the framework of a collaboration between the Center of Studies and Activities for Space of the University of Padova (CISAS-UPD) and the Japan Aerospace Exploration Agency (JAXA), 45 hypervelocity impact experiments were realised on Carbon Fibre Reinforced Plastic samples (CFRP) having nominal thickness of 2.3, 3.5 and 4.3 mm. The impact tests were made with aluminium spheres of 0.8, 1.5, 1.9, 2.3 and 2.9 mm, at velocities between 2 and 5 km/s. After a preliminary post-impact inspection of the targets, ballistic limit equations were developed using a new procedure which permits to estimate the uncertainty in the failure predictions starting from the measurement of the projectile entry crater. Then, in case of sample perforation and consequent ejection of fragments, high-speed shadowgraphs of the debris cloud were analysed to qualitatively describe the evolution of the impact damage, together with its basic features.