Tensile behaviour of glass fibrereinforced acetal polymer

Tensile behaviour of glass fibrereinforced acetal polymer

SCHUSTER, D. M. and REED, R. P. Fracture behaviour of shock-loaded boron-aluminium composite materials Journal of Composite Materials, 3, p 562 (Jul...

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SCHUSTER, D. M. and REED, R. P.

Fracture behaviour of shock-loaded boron-aluminium composite materials

Journal of Composite Materials, 3, p 562 (July 1969) Composite materials of aluminium alloys and boron filaments aligned in two mutually perpendicular directions were subjected to impacts in directions normal to the plane of reinforcement in order tb determine dynamic tensile fracture behaviour. Materials with a matrix of aluminium and brazing alloy made by plasma spraying and vacuum brazing show both tensile fracture and filament damage, while those made by plasma spraying and diffusion bonding into an aluminium matrix are damaged mainly by filament fracture. The possibility of the utilization of shock wave attenuation by the filaments in the design stage of composite materials is suggested. (69/3/16)

VIDOZ, A. E., CAMAHORT, J. L. and CROSSMANN, F. W. Development of nitrided boron reinforced metal matrix composites

Journal of Composite Materials, 3, p 254 (April 1969} The production of a submicron coating of boron niti'ide on boron filaments is reported as substantially improving their stability in matrices of aluminium alloys, titanium based eutectics and nickel. The coating permits the fabrication of nitrided boron/ aluminum composites with low filament degradation, high concentration and good interfacial bonding. The mechanical properties of some nitrided boron/aluminium composites prepared by continuous liquid infiltration are discussed .as a r e the effects o f heat treatment on these properties. (69/3/17)

WOI, FF, E. G.6, Hydrodynamic alignment of discontinuous fibres in a metal matrix

Fibre Science and Technology, 1, No 4, p 307 [April 1969J Hydrodynamic principles are applied t o a process in which discontinuous fibre/metal composites are m a d e by electrodeposition of the metal matrix around the fibres. The control of factors such as fibre • alignment and

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COMPOSITESDecember 1989

distribution in the finished composite are considered theoretically and ex• perimentally for deposition between rotating cylinders, where electrolyte flow is circular, and f o r deposition between parallel plates where it is linear. The advantages and disadvantages of both types of electrolyte flow when used for composite fabrication are enumerated. (69/3/18)

Resin Matrices

ASHBEE, K. H. G. and WYATT, R. C. Water damage in glass fibre/resin composites

Proceedings of the Royal Society, A312, No 1511, p 533 (30 September 1969] An examination o f composites of polyester resin and glass fibres which had been exposed to water at 20, 60 and 100°C shows that at all three temperatures the bond between resin and glass is rapidly destroyed by diffused water. For E ' a n d C glass fibres debonding is due to interracial pressure caused by selective leaching of soluble impurities in the fibres, while for relatively pure silicon fibres the phenomenon is due to high interfacial shear stresses which result from resin shrinkage. On the addition of a coupling agent, failure is delayed until compressive shear stresses of sufficient magnitude are produced by resin shrinkage. (69/4/10)

ASHTON, J. E. and LOVE, T. S. Experimental study of the stability of composite plates

Journal of Composite Materials, 3, p 230 (April 1969] An experimental determination of the critical buckling loads for boron-epoxy composite plates is described and analytical predictions which were obtained by the use of lamination theory and orthotropic lamina properties measured with sandwich beams are given. Good agreement between the experimental and analytical results is shown for symmetrical and unsymmetrical plates and for ortho, iso and anistropic plates. Evidence is presented which suggests that unsymmetrically laminated plates can be analysed by means of an uncoupled analysis with a reduced stiffness matrix. (69/4/11)

BELL, J..P.

Flow orientation of short fibre-eom, posites

Journal of Composite Materials, 3;:0_ 244 (Apri! 1969} A system consisting of 50 volume % o f glass fibres in an epoxy resin is examined in order to determine the parametres which affect fibre orintation during flow. Feed material consists of pellets containing preorientated glass fibres and steel tracer fibres which are observed through the walls of a glass rheometer. Above and below the rheometer constriction little fibre re-orientation occurs but f e e d particles are found to be sheared into strands .at that point; the dependence of extrusionpressure o n extrusion rate is found to be less than for unfilled systems. (69/4/12)

GARLAND, D.

Fire resistance of GRP improved by Normanite asbestos

Reinforced plastics, 13, No 10, p 264 (1969J The partial survival of Normanite reinforced plastics during an accidental fire led to an investigation of the fire resistance of such materials. Comparitive rate o f burning tests with glass fibre chopped strand mat and Normanite type A indicated that the rate of burning was lower for Normanite laminate made with a GP resin despite the much higher resin •content. Moreover fire penetration was much less in Normanite compared to a GRP with fire resistant resin .and twice the weight of reinforcement. (69/4/13)

HARDY, G. F. and WAGNER, H. L. Tensile behaviour of glass reinforced acetal polymer

fibre-

Journal of Applied Polymer Science, 13, No 5, p 961 [1969) The observed tensile behaviour o f acetal polymers containing glass fibres is described in terms of a model in which the fibres are categorized into groups orientated parallel to and perpendicular to the axis o f the applied load. The model gives two constants, one of fibre efficiency for parallel fibres and the other, of matrix restraint imposed by the perpendicular fibres.

Mention is made of tile addition of ammonium chloride to the powdered polymer before the fibres are added in order to control tensile strengths and elongations to fracture without gross alterations to fibre geometry, surface finish or matrix properties. (69/4/14)

HARDY, N. E. Carbon fibres: Part 1 state of art Part 2 tensile testing

Engineering, Materials and design, 12, No 9, p 1325 (September 1969) In part 1 fabrication methods for carbon fibre reinforced plastics are reviewed. The older leaky mould technique is dealt with briefly before proceeding to pre-preg lay-ups, filament winding and injection moulding. The machinability and use of CRFP cladding are also discussed. Part 2 deals with the use of the lnstron tensile testing machine in evaluating the strengths of single fibres and CR FP composites. (69/4/15)

HAYASHI, I. and YOSHIKAWA, K. Low cycle fatigue and PVC-Nylon composite hose

creep

of

Proceedings Of the 12th Japanese congress on materials research, p 176 {1969] Static tensile, pulsating tension fatigue, and creep tests were carried out on PVC hose reinforced longitudinally and spirally with nylon fibres, in order to clarify the relationship between the strength of the composite and those of its components. Results show that a superposition rule can be applied to static tensile strengths, but such a rule for fatigue and creep strengths gives values lower than the experimental ones. The creep rupture times and number of cycles to rupture were greater for a mono-warp test piece than for a t13 fibre test piece. (69/4/1 6)

and the effect of fibre volume fraction on tensile and flexural strengths related to the Kelly Kyson equation. Strengthening factors are calculated for each fibre volume fraction and discussed in terms of polymer structure while the effects of fibre fraction on toughness and notched bar i m p a c t strength are also evaluated. The effect of interfacial water is shown by comparisons of dielectric constants and dissipation factors of wet and dry composites and the differences in wet and dry strengths used to illustrate the effects of it on interfacial bonding. (69/4/17)

LEE, L. H. and RIEKE, J. K. Glass-reinforced PE versus ethylene/ acrylic acid copolymers

Modern Plastics, 46, No 8, pp 98 110 (August 1968} Adhesion at the glass-resin interface is improved by grafting of high density polyethylene with acrylic acid. This is demonstrated by scanning electron micrographs. The glass-filled copolymer shows a general improvement in mechanical properties, notably tensile strength and notched impact strength, over the homopolymer, but this improvement is specific to the graft copolymer, the low modulus random c o p o l y m e r being inferior. The fatigue life under cyclic loading conditions is also greater for the graft copolymer than for HDI'E. (69/5/18)

Strength-composition relationships of randon short glass fibre-thermoplastics composites

Polymer Engineering and Science, 9, No 3, p 213 (May 1969) The strength/composition relationships of twelve glass-fibre/thermoplastic composite systems are studied

MATSUO, M. Fine structures and fracture processes in plastic/rubber two-phase polymer systems 2 - observations of crazing behaviburs under the electron microscope

Polymer Engineering and Science, 9, No 3, p 206 {May 1969} The use of an osmium tetroxide staining and hardening technique enables a study of crazing behaviour in several plastic/rubber two-phase polymer systems to be made by direct observation of thin sections under the electron microscope. Relationships between the dispersed rubber particle~ and crazing behaviour are discussed and it is concluded that crazes usually start at the boundaries of the particles, particularly the larger ones, and propagate through them in a direction perpendicular to the applied stress. It is noted that although the rubber particles are deformed with craze formation in the stress direction their radii in the perpendicular direction remain almost constant. (69/5/20)

POWELL, D.

MATSUO, M., NOZAKI, C. and JYO, Y. Fine structures and fracture processes in plastic/rubber two phase polymer systems, 1 - observation of fine structures under the electron microscope

Polymer Engineering and Science, 9, No 3, p 197 {May 1969] LEE, L. H.

ient contrast for their direct observation by transmission electron microscopy. The fine structures illustrated arc discussed briefly in relation to the dynamic viscoelastic properties of the systems and widespread application of tile examination technique is predicted in the determination of structure/ property relationships. (69/5/19)

The technique of the exposure of specimens to osmium tetroxide vapour at room temperature for several days enables the fine structures of several plastic/rubber polymer systems including blends and graft copolymers to be observed directly. This selective hardening and staining procedure allows ultra-thin specimens to be cut and endows fine structures with suffic-

Marketing reinforced plastics in the building and construction industry

Plastics and Polymers, 37, No 130, p 301 {August 1969} The article discusses the efforts of the reinforced plastics industry to sell to the building and construction industry which is a large potential market for its surplus production capacity. Organised marketing must take into account the restricted requirements, stability, "and well defined communication channels characteristic of the construction industry. Tile challenge of well tried traditional materials with many advantages must also be faced. Nevertheless, in 1967 20% of all plastics p~oduction went into building applications in Britain, and 30% in Germany. (6915121 )

COMPOSITES December 1969

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