Evaluation of Shielding Performance of Composite Laminates under Hypervelocity Impact

Abstract

High performance fiber fabrics are widely used in whipple structures to resist hypervelocity impact (HVI) of man-made debris or meteorites. Evaluation of the shielding performance of fabric-reinforced composites poses a great challenge when considering the local feature of fiber compression and damage under shock loading. A momentum diagnostic approach is developed in this paper to quantitatively determine the characteristics of momentum distribution of a debris cloud, which lays the basis for assessing a whipple shield.Efforts have been made to bring forward a systematic scheme for quantitative evaluation of a whipple shield. The bumper of a whipple is evaluated by measuring the spatial distribution of a debris cloud resulted from projectile/bumper collision. For a rear wall resisting discrete impacts of a debris cloud, two experimental schemes are applied consisting of micro fragments impact test to assess the material toughness against fragment penetrations, and planar impact test to evaluate the capability of energy absorption. Comprehensive tests were performed for fabric laminates and aluminum alloy coupons. It is evidenced that fabric laminates has the advantages of separating into fine fragments at collision speeds of 4-6km/s, and of reducing efficiently the shock intensity under a short shock pulse, not to mention its extremely high strength in nature. Hence, fabric laminates is of excellent selections both for a bumper and a rear wall. The experimental schemes being established afford a feasible way for optimization of a laminates combination.