Investigation of the high velocity impact behavior of grid cylindrical composite structures

In this paper, the experimental behavior of grid cylindrical composite structures, which are used widely in engineering structures, under ballistic impact is investigated. For this purpose, some grid cylindrical composite specimens were manufactured by the filament winding process and perforated by projectile using the ballistic gas gun. Incident impact velocity and exit velocities of projectile were recorded in each test. The results show that the presence of the ribs prevents pervading of damaged area of one cell to its adjacent cells. The structure behaves differently against projectile with velocity near ballistic limit and higher velocities. The results demonstrated that, by getting close to the ribs location, ballistic limit velocity was increased. However, due to reduction in energy absorption mechanisms in grid composite structures which are impacted in higher velocity than ballistic limit, projectile was exited of grid samples at higher velocity than unstiffened composite shells. Also, investigation of delamination in composite shell and ribs, debonding between ribs and shell (or separation of ribs and shell), residual velocity of projectile, damaged area of the grid specimens and the effects of curvature in two different velocities are presented and the results are discussed. POLYM. COMPOS., 38:2603–2608, 2017. © 2015 Society of Plastics Engineers