Ballistic impact behavior of aeroengine composite casing

To obtain the dynamic response, damage and failure modes of fiber reinforced composites used as aeroengine fan containment casing under conditions of fan blade out event, ballistic impact tests were conducted on Kevlar woven fabrics laminates in gas gun employing the rectangular blade projectile. It was concluded that when the thickness of composite target increased by 25%, the energy absorption increased 92%. With the increase of blade projectile initial velocity, the damages of composite target became more severe from the slight dent to transverse and longitudinal cracking coupled with delamination failure. After the impact velocity increased over the ballistic limit, the damage turned to the rectangular hole in the impact surface and fiber rupture, fiber pullout and delamination failure in the exit surface. Under the impact of blade projectile, bulge deformation generated in the local contact area of the composite laminate, which recovered after the projectile perforates or rebounds. The roll angle of blade projectile led to larger influencing area due to the orthotropic characteristic and consequent improvement of impact resistance.