摘要: This report contains 3 sections: (1) the tensile strength of roving bundles of S-2 Glass fibers (quasistatic strength of 535 + or - 16 ksi) is measured using a modified split Hopkinson bar with two specimen designs at strain rates... 展开 This report contains 3 sections: (1) the tensile strength of roving bundles of S-2 Glass fibers (quasistatic strength of 535 + or - 16 ksi) is measured using a modified split Hopkinson bar with two specimen designs at strain rates 103/S . The mean tensile strength measured from one sample design is 700 + or - 150 ksi at a strain rate 600 s-1 500 + or - 120 ksi at a strain rate Of 1200 s-1 from the other. There is a very good agreement on the monofilament strength derived from the statistical analysis of the stress-strain data obtained from the two sample designs. (2) A reverse impact technique to measure the force on projectile noses penetrating fiber reinforced plastic target panels is presented. 50 mm diameter GRP and KRP flyers are impacted against different nose-shaped steel bar targets instrumented with manganin gauges. The penetration into the 12.7 mm thick GRP is steady for the flat nose bar, but transient for the conical and hemispherical nose shapes. The penetration into the 37.4 mm thick KRP is steady for the conical and hemispherical nose shapes. (3) Five modes of failure (shock, double shear, single shear, cavity expansion, tensile stretching) of S-2 Glass composites during penetration with different nose-shaped projectiles are identified. The shock stage is especially dominant in flat nose-shape projectiles and a simple model is presented. 收起