On the ballistic response of an aerospace-grade composite panel to non-spheroidised fragment simulants

Abstract

The low mass and high specific strength of composite systems has led to their widespread adoption in aerospace applications. Consequently their performance under impact from off-normal events, or even deliberate insult, for example from a munition such as an anti-aircraft missile, is of paramount importance. Experimental and computational work to-date has typically focused on the response of composite systems to impact from projectiles with simple spherical or cylindrical geometries. However, such geometries are not representative of the full range of likely threats. In addition, even within this simple set of constraints the effects of projectile geometry on composite response under impact have been highlighted. Here an attempt has been made to investigate the effect of more complex geometric structures – comprising two-dimensional flat and peaked-nosed structures – on composite systems. A series of ballistic tests were carried out accelerating various geometric ‘fragment simulants’ into an aerospace-grade composite material. Damage was monitored in real time using high-speed cameras. Resultant calculations of projectile energy loss in the target, combined with analysis of recovered material via ultrasonic c-scan, have shown a clear relationship between projectile geometry and CFRP failure mode.