Normal and oblique hypervelocity impacts on carbon fibre/peek composites

Improvement of methods for evaluating the spacecraft pressure wall penetration probability

“…twice the honeycomb core), ~4.6 times the impact energy is required to reach the ballistic limit. An impact traversing a 45 mm deep core "sees" twice as much honeycomb material as an impact traversing a 22 mm deep core; the doubling in impact energy required to reach the ballistic limit is consistent with this visualisation [Taylor et al, 1999].…”

“…This prevents comparison of the relative performance of different configurations. Therefore, caution has to be exercised before extrapolating data to untested materials or configurations [Taylor et al, 1997a[Taylor et al, , 1997b[Taylor et al, , 1999. Some composite materials have however demonstrated their efficiency in specific conditions Lambert, 1995;Shiraki, 1996;.…”

“…The need for in-depth consideration of composites' characteristics like orthotropy and compaction has also been demonstrated . Taylor et al, 1999, have applied the modified Cour-Palais equation to characterise the ballistic limit of an Envisat-type CFRP / Al single-honeycomb panel. The equation can be applied conservatively to particles impacting at angles of incidence greater than 15°.…”

“…• The debris cloud is channelled for both normal and oblique impact angles [Taylor, 1999;Lambert, 1997;Jex, 1970]. …”

“…This approach, however, means that the influence of the honeycomb core is not represented in the equation. For some honeycomb configurations, this equation may be consistent with the normal incidence data; the use of either equivalent spacing [Sennett & Lathrop, 1968] or equivalent rear facesheet thickness [Taylor et al, 1999]. Due to the influence of the impact angle on the honeycomb structure shielding performance, the Christiansen-Cour-Palais equation cannot be used to represent the impact angle dependence for honeycomb structure targets.…”