Normal and oblique penetration of woven CFRP laminates by a high velocity steel sphere

Abstract

In this research two thicknesses of a woven CFRP laminate have been subjected to impact by a steel sphere in a velocity regime ranging from 170 m/s to 374 m/s. Impact and penetration of targets at normal and oblique incidence were studied using high speed video. For the normal incidence targets at the higher velocities of impact, a conical mass of laminate was ejected ahead of the projectile. Furthermore, despite the energy transferred to the plate increasing with impact energy, the degree of delamination in the thicker targets decreased indicating a change in projectile penetration mechanism. Eventually, the degree of delamination in the thicker targets appeared to approach an asymptotic level whereas for the thinner targets the degree of delamination appeared constant regardless of impact energy. For oblique targets more of the kinetic energy was transferred from the projectile when compared to the same thickness of target that had been subjected to a normal incidence impact. However, this was merely due to a geometrical effect. Further, thicker panels appeared to behave more efficiently by absorbing more kinetic energy per effective linear thickness at the lower impact energies Composites Part A: Applied Science and Manufacturing 39 (5), pp. 866-874 (2008) 2 where petalling is a dominant factor in the penetration. This advantage appeared to disappear as the impact energy was increased.

Analytical modelling of high velocity impacts of cylindrical projectiles on carbon/epoxy laminates

“…However, the number of papers concerned with the impact response of carbon fiber laminates under impact at hundreds of meters per second is relatively small. Experimental results of steel projectiles impacting CFRPs at high speed velocities can be found in papers due to Cantwell and Morton [11], Sun and Potti [12], Larsson [13], Bland and Dear [14], López Puente et al [15,16], Will et al [17], Tanabe et al [18,19], Hammond et al [20], Hosur et al [21], Herzsberg and Weller [22], Caprino et al [23] and Hazell et al [24]. Other authors used projectiles made of different materials: Kim et al [25] utilized ice spheres, Chambers et al [26] lead pellets and Asp and Juntikka [27] ice spheres and granite stones.…”

Penetration of a woven CFRP laminate by a high velocity steel sphere impacting at velocities of up to 1875m/s

“…Hazell et al [4] have previously shown that below an impact energy of 500 J, the energy absorbed by 3 mm and 6 mm plates dropped off and appeared to approach an asymptotic level. For a 6-mm thick CFRP panel, the level of damage also appeared to drop off and approached a constant level whereas with the 3 mm target the level of damage appeared to be constant regardless of the impact energy.…”

Characterization of microscopic damage due to low-velocity and high-velocity impact in CFRP with toughened interlayers

“…Tanabe et al (2003) studied the fracture behavior of CFRP using different types of carbon fiber and they concluded that the mechanical properties at rear layers contribute to improve the energy absorption. Hazell et al (2008) studied damage mechanism of CFRP when subjected to normal and oblique impact at a high velocity. On the other hand, in terms of low-velocity impact, Mitrevski et al (2005) studied the effect of various projectile shapes, namely, hemispherical, conical and ogival.…”