Ballistic impact resistance of graphite composites with superelastic SMA and Spectra hybrid components

Abstract

The effect of adding small amounts of high strain hybrid components on the impact resistance of graphite epoxy composites subjected to projectiles traveling at ballistic velocities (greater than 900 ft/sec) has been studied.The hybrid components tested include superelastic shape memory alloy (SMA) and a high performance extended chain polyethylene (ECPE) known as Spectra™.From testing 1.2% volume fraction superelastic SMA fiber layers embedded on the specimens front, middle, and backface, it was concluded that the backface was the most suitable location for a high strain hybrid component since the hybrid component is not restricted from straining by surrounding graphite material. However, no significant increases in energy absorption were found when two perpendicular SMA layers were tested on the backface. In all cases, the embedded SMA fibers were pulled through the graphite without straining to their full potential. It is believed that this is due to high strain rate effects coupled with a strain mismatch between the tough SMA and the brittle epoxy resin. However, a significant increase in energy absorption was found by adding ECPE and ECPE/SMA layers to the backface of the composite. With a 12% increase in total composite mass, a 99% increase in energy absorption was observed.

The effect of hybridization on the GFRP behavior under high velocity impact

“…Thus, embedding super-elastic SMA fibers in the composites could make the composites tougher and increase the damage impact resistance of composite structures [10]. It was found by Ellis et al [11] that the SMA fibers were more effectively used when embedded in the more ballistically compatible, higher strain, thermoplastic rubber resin. A 99% increase in energy absorption was observed by adding small amount of high performance extended chain polyethylene (ECPE) fiber prepreg, knowing as Spectra Shield TM , with only a 12% increase in total composite mass.…”

On the Mode I and Mode II Delamination Characteristics and Surface Morphological Aspects of Composites with Carbon-Thermoplastic Hybrid Fabrics and Innovative Liquid Thermoplastic Resin

“…Concerning the hybrid composites with hybrid fabrics (carbon + thermoplastic fabrics), the majority of the work which has been reported in the literature is concentrated on studying the tensile, fatigue, impact, and damping characteristics of these hybrid composite structures [ 2 , 18 , 27 , 28 , 29 , 30 , 31 , 32 ]. However, there is very limited research on understanding the fracture toughness attributes of composites with hybrid thermoplastic fabrics.…”

A novel lightweight sandwich panel with substantial resistance to ballistic penetration

“…Adding a rigid front surface is beneficial because it helps spread the impact forces over a broader area while blunting and slowing the projectile. For example, a hard ceramic plate-like structure plus one or more compliant intermediate layers can be laminated to the front facing sheet [9,10]. In applications that can tolerate panel perforation, anti-spall liners can also be secured to the rear facing sheet to capture and retain penetrating fragments or spalled chips.…”