Properties Of Fibrous Materials Research Articles

Structure and adsorption properties of fibrous materials based on silica

1. A superthin multilayer fiber, Sivol, has significantly more developed porosity in comparison to the starting material, chrysotile asbestos. The values of S and the pore volume of Sivol are one order of magnitude higher than for chrysotile asbestos. 2. In contrast to Silokhrom, the adsorption values of CH3OH and H2O for Sivol and the silica fiber and the values of S calculated from the adsorption isotherms of these substances are significantly higher than the values measured with cyclo-C6H12 and krypton due to the specific interaction of the molecules of CH3OH and H2O with the surface of the adsorbents and the presence of fine pores in them.

Composites in Shock and Vibration Isolation

The investigation is concerned with the control of force transmitted to the support caused by central normal impact of a projectile on a plate supported by composite isolators with constrained rattle space. Normally isotropic isolators with appropriate low stiffness will absorb appreciable amount of impact energy. But this requires some space (rattle space) for deflection when the plate is subjected to projectile impact. In certain applications (such as plates used as armor in combat aircraft) there is not enough space for the plate to move normal to the plane of the plate. In the present analysis, by using composite isolators the plate is allowed to rotate in the plane of the plate so that less space (rattle space) is required normal to the plane of the plate. By allowing the plate to rotate in its plane, the impact energy is absorbed in the rotational direction in addition to the usual normal to the plane of the plate; thereby transmitting less force to the support compared to the case with isotropic isolators. A method of controlling the force transmitted to the support is to control the natural frequency of the system. In the present analysis the influence of fiber orientation and material properties on the natural frequency of the plate and composite support system is shown.

Stability of thick angle-ply composite plates

An eight-noded quadratic rectangular element is developed in order to study the stability aspects of a layered rectangular composite plate under biaxial loading. The element has five degrees of freedom per node. The formulation includes the Mindlin-type nonlinear strain-displacement relations. The adoptability of the element is demonstrated by solving a number of problems for which results exist in the literature. The effects of fibre orientation, material properties, layering and boundary conditions on the buckling load are studied in detail. The deficiency of earlier reported results is also pointed out.

Properties of fibrous materials which have been treated in a gas discharge

As a result of treatment of fibrous materials with a gas discharge plasma, their physicomechanical properties are changed.

Improving the properties of fibrous materials prepared by the aerodynamic spinning method

It has been shown that fibrous materials from yarns having a six-armed profile or a six-armed profile with an interior cavity have 1.3 times greater strength as compared with material from round yarns at an equal surface density.

Physicomechanical properties of porous fiber materials and prediction of them

A comparison is presented of the experimentally determined values of certain properties of porous fiber materials obtained by the optimum method from monodisperse fibers of copper, nickel, and Nichrome of different diameters with the corresponding theoretical values. The electrical conductivity, tensile strength, and modulus of elasticity, the basic properties of a porous body, which are determined both by the structural characteristics of the elements and by the condition of the interparticle contacts, were considered.

Constitutive relations for the thermomechanical behavior of fiber-reinforced inelastic laminates

The thermomechanical behavior of laminated composites in which every lamina is unidirectional fiber-reinforced thermoinelastic material is determined by a micromechanical analysis followed by a macromechanical one. In the micromechanical analysis, effective constitutive relations are derived for unidirectional fibrous materials in which the matrix and fiber phases are thermoelastic in the linear region and thermoinelastic in the nonlinear region. The derivation is based solely on the material properties of fibers and matrix and amount of reinforcement. By a macromechanics analysis the gross behavior of the laminated composite in stretching and bending deformation is determined. Applications are given for the deformation field developed in cooling and reheating of graphite/aluminium laminated plates.

Thermophysical properties of porous fiber materials

Thermophysical properties of porous fiber materials

A Multi-Stage Apparatus for Characterizing the Cyclic Torsional Fatigue Behavior of Single Fibers

Torsional fatigue properties of textile fibers subjected to low cyclic torsional strain amplitudes are sensitive to the molecular structure and orientation. Multi-stage in strumentation capable of generating continuous oscillatory torsional strains and mon itoring times to failure is described. Examples are presented of fiber surface and internal morphologies of cotton, acrylic, and Kevlar® fibers caused by torsional fatigue at low strain amplitudes.

Heat-induced changes in the properties of kaolin fiber materials

The behavior of the fibrous material in service depends essentially on the structure which the product acquires during its manufacture and on the composition of the bonding substance.

Strength properties of porous fiber materials with an oriented structure on a stainless steel base

Strength properties of porous fiber materials with an oriented structure on a stainless steel base

The thermo-acoustic properties of fibrous material

The compressibility of air inside a loudspeaker enclosure can be increased if the enclosure can be made isothermal. Stuffing fibrous material into an enclosure tends to make it isothermal since the material acts as a heat sink. In order to evaluate the effectiveness of filling material in loudspeaker enclosures, the thermal time response of fibrous materials is calculated. The time response is found to depend on the density of the material and the radius of the fibers. The frequency response of a typical fiberglass material is presented.

Strength properties of high-porosity metal fibre materials : Kostornov, A.G., Shevchuk, M.S. and Gorb, M.L. Soviet Powder Metallurgy and Metal Ceramics, Vol 11, No 4 (Apr 1972) pp 326–329

Strength properties of high-porosity metal fibre materials : Kostornov, A.G., Shevchuk, M.S. and Gorb, M.L. Soviet Powder Metallurgy and Metal Ceramics, Vol 11, No 4 (Apr 1972) pp 326–329

The Real and Imaginary Parts of the Complex Viscoelastic Modulus for Boron Fiber Reinforced Plastics (BFRP)

The general viscoelastic model was chosen to represent the mechanical properties of boron fiber reinforced plastics (BFRP). The experimental configuration selected was that of a thin beam subjected to transverse vibration. The mechanical properties of the beam (in the direction “x” parallel to the length of the beam) then manifest themselves in the form of a viscoelastic complex modulus, Exx* = Exx′+iExx″. In this investigation the purposes were to define parameters relative to the dynamic material properties of boron fiber reinforced plastic (BFRP), to establish quantitative values for these parameters by experimental measurement, and to compare these quantities for BFRP with the same parameters for a metallic material such as aluminum 2024-T4 alloy. Born laminates used in these studies were fabricated from NARMCO 5505 preim-pregnated boron fiber epoxy tape. Plots of storage modulus Exx′ and loss modulus Exx″ as a function of excitation frequency are presented for three fiber orientations, 0° (unidirectional), ±45° (crossply), and 90° (all transverse). Also presented is the damping (or loss) factor, nxx, as a function of excitation frequency for the three above-mentioned fiber orientations. The values obtained for damping factor are compared with those obtained by measuring the exponential decay of BFRP beams initially excited in the free-free mode of vibration. Damping factors obtained from free-free vibration experiments were lower than those obtained from the forced vibration experiments for all materials concerned.

Manufacture and properties of powder metallurgical refractory compound fibers and porous fiber materials

1. Using titanium carbide and titanium and zirconium diborides as typical examples, a study was made of the extrusion of fibers from plasticized powder mixtures. The optimum mixture compositions and extrusion conditions, ensuring stability of filament discharge, were determined. 2. Certain characteristic features of the sintering behavior of refractory compound fibers were discovered. Conditions securing maximum possible strength in sintered refractory fibers were determined. Ways of further increasing their strength are discussed. 3. Porous materials were produced from sintered fibers. It is shown that the hydraulic properties of fiber filters approach those of filters from wire fibers. Fiber filters are comparable in strength to porous materials from powders and can be expected to surpass them in stopping power.

Strength properties of high-porosity metal fiber materials

Strength properties of high-porosity metal fiber materials

Use of extremely thin basalt fibers for cleaning and sterilizing air

The results obtained in comparative tests of the filtering properties of various fiber materials showed that ultrafine basalt fibers had definite advantages when used as filter elements in the filtration of industrial air.

Some physical properties of high-porosity bodies

1. A porous body model in which both equiaxed (spheres) and nonequiaxed (cylinders) material elements are considered leads to finite physical properties over the whole porosity range. 2. The porous body model proposed is appropriate both for powder and fiber porous bodies. 3. The physical properties (conductivity, modulus of elasticity) of powder and fiber porous bodies are similar at low porosities. At higher porosities (above 0.5), the properties of fiber materials are much higher than those of powder bodies; the stronger the dependence of a given property on porosity, the greater is this difference.

Some problems of fiber metallurgy

Problems of the preparation and sintering of fibers are discussed, and the properties of porous and dense copper fiber materials are studied. Fiber metals differ from powder metals by the following characteristics: pronounced anisotropy, considerable elastic recovery during sintering and compacting, greater dependence of properties on intraparticle factors, and lesser dependence on interparticle contact factors.

Physical Properties of Textile Fibers. W. E. Morton and J. W. S. Hearle. Manchester and London, the Textile Institute and Butterworths, 1962. xxi + 608 pp. Price 105s ($14.70)

Physical Properties of Textile Fibers. W. E. Morton and J. W. S. Hearle. Manchester and London, the Textile Institute and Butterworths, 1962. xxi + 608 pp. Price 105s ($14.70)