航空发动机复合材料机匣弹道冲击特性

为获得复合材料作为风扇包容机匣时遭受叶片冲击载荷时的动态响应、损伤与失效模式,在空气炮装置上使用叶片形弹体对Kevlar织物层合板开展了弹道冲击试验,结果发现:复合材料靶板厚度提高25%,复合材料靶板吸收的能量提高约92%；随着叶片弹体速度的增加,复合材料靶板的损伤破坏逐渐严重,从轻微的压痕,转变为横向和纵向裂纹与分层损伤,再转变为矩形穿孔,同时靶板背面出现纤维断裂、纤维拔出与分层失效等现象；在叶片弹体撞击下,靶板上在与弹体接触的局部区域形成鼓胀变形,并在弹体击穿或反弹后发生变形回复；叶片弹体的横滚角将导致叶片的作用范围增大,使得靶板抗冲击性能有所提高。 

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.