Perforation of Sandwich Panels with Honeycomb Cores by Hemispherical Nose Projectiles

Abstract

Analytical models for the static and low-velocity perforation of composite sandwich panel with woven E-glass/epoxy prepreg facesheets and aluminum honeycomb core are developed. The analytical models are based on a set of experimental results. A three-stage perforation process involving consecutive failures of top facesheet, core, and bottom facesheet is proposed. The analytical predictions of static failure loads and deformation are within 10 and 8% of the test data, respectively. The predicted ballistic limit is within 10% of the test data, while the total energy dissipated at the ballistic limit is within 18% of the test results.

Ballistic impact experiments of metallic sandwich panels with aluminium foam core

“…Similar experiments have been carried out by Roach et al [16,17] on PVC foam core panels, where the role of core and the relationship between the energy absorbed and delamination area were studied as well. Hoo Fatt and co-workers [18,19] developed analytical solutions for the ballistic limit of a honeycomb core sandwich plate subjected to normal impact by projectiles with different shapes, in which the overall bending and stretching of the plates were considered. Kepler [20,21] experimentally and theoretically investigated the perforation performance of PVC foam core panels and three main damage modes were identified and formulated mathematically.…”

A Comparative Study of Ballistic Resistance of Sandwich Panels with Aluminum Foam and Auxetic Honeycomb Cores

“…Therefore, they have been employed as energy absorbers in a wide range of applications involving extreme loading conditions such as ballistic impacts. Most of the existing efforts on the ballistic impact of sandwich structures with conventional honeycomb cores have focused on the out-of-plane scenarios when the projectile moves along the axis of the honeycomb core [1,2], as depicted in Figure 1. The effects of several parameters on the energy dissipation of sandwich panel during axial perforation were experimentally tested by Goldsmith and Sackman [3], including the impact velocity, the boundary condition, and the bonding strength between the honeycomb core and the aluminum faces.…”

Effect of post-cure temperature and different reinforcements in adhesive bonded repair for damaged glass/epoxy composites under multiple quasi-static indentation loading

“…The effects of post-cure temperature on the local bending response of the repaired glass/epoxy specimens were investigated by performing quasi-static indentation tests on specimens exposed to post cure temperature at ambient temperature (30ºC) and elevated temperatures until up to glass transition temperature of epoxy resin (50, 70 and 90ºC). Quasistatic indentation has a limited coverage in literature so far: a few studies exist on filamentwound tubular structures e.g., subjected to weathering [39] or honeycomb sandwich panels [40], but are more related to the measurement of perforation energy than to the assessment of residual indentation after moderate and repairable damage, hence also after repair. This comes to the innovative content of this work, which tries to compare different repair methods as far as their effectiveness to cope with further indentation damage is concerned, therefore leading to some prolongation of the service life for components, which is of interest for industrial applications.…”