HIGH VELOCITY IMPACT TESTS ON STITCHED GRAPHITE/EPOXY LAMINATES

摘要

Stitched graphite/epoxy laminates, having thicknesses in the range 1.5 to 6 mm, were subjected to ballistic impact. Two steel spheres, 12.7 mm and 20 mm in diameter, were used as bullets during the tests, carried out at two different speeds. From the results, the effect of thickness on the perforation energy was similar to what observed in low velocity impact. However, a different relationship was seemingly verified between the perforation energy and the projectile diameter, passing from low to high velocity. The delamination extent was strongly influenced by the bullet speed, with lower damage areas pertaining to high velocity; however, when sufficiently thick specimens were considered, the delaminated area was unaffected by speed.