Predicting the Perforation Response of Honeycomb Sandwich Panels Using Ballistic Limit Equations

Abstract

Man-made debris from previous spacecraft missions poses a serious threat to spacecraft that are launched to operate in Earth orbit because it can strike such spacecraft at extremely high velocities and consequently damage mission-critical systems. Most satellites are constructed with honeycomb sandwich panels as their primary structural elements. To be able to perform a risk analysis, it is important to know, in the event of such a meteoroid or orbital debris particle impact, whether or not the impacting particle or parts thereof will exit the rear of the sandwich panel.A recently developed set of ballistic limit equations for two different types of honeycomb sandwich panels are studied to determine how well they perform when they are applied to systems that are outside of the database that was used to develop them. It was found that these ballistic limit equations are fairly conservative; they successfully predicted sandwich panel perforation in nearly all of the tests that resulted in perforation, while allowing approximately half of the nonperforating tests to be incorrectly labeled as tests with a perforation. This indicates the likelihood that use of these equations in design applications could result in overly robust shielding hardware.Nomenclature d c = critical projectile diameter for failure of rear wall, cm d p = projectile diameter, cm K MLI = adjustment factor for multilayer insulation K S2 = adjustment factor for scaling standoff distance S 2 in the hypervelocity regime K tw = adjustment factor for equipment cover plate thickness t w in the hypervelocity regime K 3D , K 3S = ESA triple-wall ballistic limit equation fit factors for the hyperballistic and ballistic velocity regimes, respectively S 1 , S 2 = standoff between first and second, and second and third bumper, where third bumper backwall, cm t b = thickness of the inner/second bumper (the rear face sheet in the case of a honeycomb sandwich panel), cm t ob = thickness of the outer bumper (the front face sheet in the case of a honeycomb sandwich panel), cm t w = thickness of third bumper/back wall/equipment cover plate, cm V, V n = impact velocity and its normal component (V cos ), respectively, km=s V t1 = transition velocity between ballistic and shatter velocity regimes, km=s V t2 = transition velocity between shatter and hypervelocity regimes, km=s V t1;n , V t2;n = normal component of V t1 cos and V t2 cos , respectively, km=s , , , , "= fit parameters for the Schäfer-Ryan-Lambert ballistic limit equation = impact angle (0 deg is a perpendicular impact on the target surface), deg ob , p = volumetric density of the outer bumper and the projectile, respectively, g=cm 3 y;ksi = yield stress of the equipment cover plate, ksi

Effects of Debris Cloud Interaction with Satellites Critical Equipments – Experiments and Modeling

“…It requires the knowledge of physical and geometrical characteristics of all subcomponents (Honeycomb definition and thickness, facesheet material and thickness…). Other investigators' developments are considered as well for implementation as they rely on a large amount of test data on various types of spaced plates structures, see for example [6][7][8] to quote a few of the numerous articles published in the area.…”

Evaluation of Space Debris Impact on Spacecraft Structure Panels

“…(3). W. Schonberg et al investigated the applicable range of the SRL ballistic limit equations by using various impact experiments on honeycomb sandwich panels having different parameters (face sheet thickness, core thickness, cell size, and foil thickness) 8) . As a result, they concluded that the SRL ballistic limit equations were conservative, because all perforation results could be predicted by the SRL ballistic limit equations but non-perforation could be predicted only 24.1% of all non-perforation experiment results.…”

Numerical Simulation of Projectile Oblique Impact on Microspacecraft Structure

“…In (4), is a particle diameter at ballistic limit, is thickness of rear wall (cm), 3 is a baseline (1.4 [15]), is rear wall yield stress, is thickness of bumper, is incidence angle, V is normal component of velocity, and is projectile density. It can be seen that the critical perforation angle of front and rear face sheet increased slowly or are unchanged with the increase of impact velocity.…”