Review on Manufacture of Military Composite Helmet

Abstract

Despite of the fact that more and more accessory devices are integrated to functionalize a ballistic helmet system, its core ballistic protective function needs to be improved with weight reduction was and still is the main course in engineering design. The two major generic classes of synthetic fibres for ballistic composites are Ultra High Molecular Weight Polyethylene (UHMWPE) fibre (0.97 g/cm3) and aramid fibre (1.44 g/cm3). In the area of military helmets, these fibres are constructed into different topologies, draping/forming into double-curvature geometric shape in multiple plies, serving as reinforcement for composite shell. The preforming ways influence the subsequent impregnation / solidification and curing step in manufacture, in terms of the fibre orientation and fibre volume fraction. The inherent structural heterogeneity thus leads to scatter in permeability and composite thickness, and have further impact in generating process-induced defects. During the processing, the fibre continuity without wrinkles, together with voids-free are determinative factors to a quality final part. The aim of this paper is to review the manufacturing technologies characterised by thermo-mechanical forming and Liquid Composite Moulding (LCM), relating their processing parameters respectively to the properties of reinforcements in one dimension (1D), two dimensions (2D) and three dimensions (3D), along with that of the matrix in dry or wet phase, interdependency of them are sought.

Analysis of Volume Fraction and Fiber Orientation on Tensile Strength and Impact Strength of Cannabis Sativa-Polyester Fiber Composites

“…Then in 1737 the plant was described in Hortus Cliffortianus by Carl yon Linne (Linnaeus) as Boehmeria nivea. Cannabis Sativa was first introduced to the Netherlands in 1733, Cannabis Sativa began to be planted in Indonesia in 1937, covering plantation areas in West Java, Central Java, East Java, North Sumatra and Sulawesi ( [17])…”

Impact‐Absorbing Thermally Dissipative Epoxy Composite Liner for Helmets

“…For example, most modern military helmets are constructed out of either one or a combination of ultrahigh-molecular-weight polyethylene (UHMWPE), carbon fibers, and aramid fibers (like Kevlar and Twaron). [1][2][3][4] To gain better perspective about composites having a high strength-to-weight ratio, it may be noted that a variation of UHMWPE, Dynamica SK99, has an average tensile modulus comparable with high-strength steels of much higher density. [5] These helmets typically comprise a few common major components, a hardtop shell to provide hardness to the exterior, shock-absorbing material to soften the blow of impact, and a fabric liner for the user to have a snug fit.…”

“…For example, most modern military helmets are constructed out of either one or a combination of ultrahigh‐molecular‐weight polyethylene (UHMWPE), carbon fibers, and aramid fibers (like Kevlar and Twaron). [ 1–4 ] To gain better perspective about composites having a high strength‐to‐weight ratio, it may be noted that a variation of UHMWPE, Dynamica SK99, has an average tensile modulus comparable with high‐strength steels of much higher density. [ 5 ]…”

A deformation model and draping behavior analysis of plain weave fabric with low-twist yarn on continuous surface

“…Han et al [10] implemented a draping simulation technique that can reflect the mechanical behavior of uncured woven fabric prepregs. The drapability of fabric is important in evaluating the deformation behavior of preform [11]. The deformation problems of fabrics have been studied by many researchers.…”