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Showing 1 to 20 of 39 for “"aramid"”.
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Structure and defects in high-performance aramid fibers
High performance aramid fibers, such as Kevlar, AuTx, and Twaron have been designed for ultra-high specific strength and stiffness. These fibers derive their superior properties from the high degree of molecular orientation that allows for efficient load transfer to the backbone covalent bond axis. …
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Limiting factors of the tensile strength of aramid fibers
… the evolution of crystallite orientation in aramid fibers during loading and their mechanical and failure behavior were investigated. Three types of as-spun aramid fibers and a heat-treated type were employed with initial distributions of crystallite orientations between 16.7º and 9.7º with …
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Fabrication and Compressive Behavior of Corrugated Aramid-Epoxy Cellular Solids
… is proposed for fabricating cellular solids from aramid-epoxy composites that can absorb impact energy and resist blunt object penetration. The aramid-epoxy samples were fabricated using wet-layup techniques, with two different styles of Kevlar 49 woven fabric in a variety of orientations. Test …
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Effect of crosslinking on aramid composites and ballistic impact resistance
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1986.
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Determination of creep, fatigue and ageing characteristics of non-metallic strength members in optical communication cables
… were two commercial brands of the para aramid polymer yarn polyparaphenylene terepthalate, also investigated were ultra high molecular weight polyethylene (UHMWPE) and E glass.<br/><br/>Assessment of the materials has been made in the light of current theories on the mechanical and …
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Design of ultra-robust supramolecular assemblies and their application to water treatment
… self-assemblies constructed from small molecule aramid amphiphiles to overcome these limitations. Aramid amphiphiles incorporate a Kevlarinspired domain that imparts strong, cohesive intermolecular interactions between molecules. This design results in the self-assembly of aramid amphiphiles into …
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Study of the rheological properties of nomex fibrids
… viscosity enhancement can be achieved by using aramid fibrids. Aramid fibrids are believed to form microstructures in suspensions because of the "space-filling" nature of their shapes and thus provide a convenient means of introducing desired rheological behavior for various commercial …
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Long term behavior of Arall laminates
The behavior of ARALL (ARamid ALuminum Laminates) subjected to tension-tension cyclic loading was experimentally investigated as a first step towards the understanding of the fatigue damage mechanisms in Arall laminates, and the relationships between damage and stiffness change, remaining strength …
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Small molecule motion within and through organic nanomaterials: an anthology
… and pertains to self-assembled small-molecule aramid amphiphile (AA) nanostructures. AAs are noteworthy within the class of self-assembled amphiphile materials because of their unusual mechanical stability borne of strong intermolecular interactions between aramid units. In Chapter 2, I …
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Standardization of test methods for property evaluation of FRP bars
… bars with different fibers (carbon, glass and aramid), varying diameters (# 3 to #8) and surface textures (ribbed, sand-coated, and sand-coated with helical wraps) were tested under this research.;Tension tests were conducted using grips made of split schedule 80 steel pipes that were bonded to …
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Transient moisture effects on the viscoelasticity of synthetic fibers and composites
… direction. Experimental results showed that aramid fibers exhibited logarithmic creep behavior under tensile load. Even though different constant moisture conditions did not have appreciable effects on the creep behavior of aramid fibers, the creep process increased substantially under …
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Supramolecular Nanostructures as Support Materials for Gold Nanoparticle Catalysts
… promising self-assembled molecule is the aramid amphiphile (AA), which overcomes the typical mechanical fragility of self-assembled structures by incorporating a Kevlar-inspired domain into its molecu- lar structure. In this work, we present a cysteine-functionalized aramid amphiphile …
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Synthesis of guanidinium-functionalized amphiphiles for the exploration of chaotropic supramolecular nanoribbons
… of time before breaking down. Aromatic amide (aramid) amphiphiles, which can form strong hydrogen bonding and pi-pi stacking between them, self-assemble into stable, mechanically strong nanofibers, in stark contrast to the assemblies that precede them. This study seeks to functionalize the …
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Combined Tension-Torsion Loading of Braided Composite Structures
… properties of carbon fibre, fibreglass and Aramid 2D tubular braided composites (TBCs) were assessed and compared under coupled tension-torsion loading. Failure mechanism of braids was investigated by the plane stress theory. A contact-free three-dimensional digital image correlation (3D …
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Avaliação da resistência mecânica e da molhabilidade de fibras de aramida após tratamento com plasma de argônio
… strength, wettability and the surface of aramid fiber treated with argon plasma. The fiber was treated with argon plasma with a vacuum of 8x10-1 bar with power of 50 and 100 Watts, and, for each voltage, tests were carried out with duration of 1, 3 and 5 minutes. The tests performed were …
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Impact damage evaluation of high performance polymeric composite material systems
… impact methods is discussed. In Part II Kevlar® aramid fiber composites, which are used as high velocity impact protection, are described. Motivation for the study of their mechanical behavior is presented, as well as the approach taken. Results showing the inverse proportionality of mechanical …
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Performance Evaluation of RC Flexural Elements Strengthened by Advanced Composites
… concentrated on the potential use of Kevlar® 49 (aramid fibre) for RC beam strengthening. <br/><br/>The main aims of research have been; (a) to investigate the relative merits of using Aramids in comparison to other FRPs, (b) strength optimisation of systems to prevent excessive losses of …
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