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A study of the effect of injection speed on fibre orientation in simple mouldings of short glass fibre-filled polypropylene
vent producing a self-reinforced composite,
Mechnical properties of aramid fibre.reinforced acrylic bone cement Wright, T.H. and Trent, P.S.Journal of Materials Science Vol 14 (1979) pp 503-505 In a significant number of cases, prostheses attached to bone with polymethylmethacrylate cement, have had to be removed due to cracking in the cement. The modulus, tensile strength, and fracture toughness of a range of aramid reinforced cements are presented, and compared with similar attempts to reinforce with carbon and metal fibres. Significant enhancement of properties is possible with the addition of low volume fractions of fibre, without modification of the cornmonly used mixing technique. Microscopy of failure mechanisms in filament-wound pipe Jones, M.C.C. and Hull, D. Journal of Materials Science Vol 14 (1979) pp 165-174) Unlined filament-wound grp pipes generally fail under internal pressurization by weepage through microcracking before their ultimate burst strength can be realized. Whitening of the pipes under load can be correlated with different types of cracking which can be predicted from the stress state in the tube wall. These cracking mechanisms have been investigated by optical microscopy, and the development of a weepage path is described, On multiple transverse cracking in glass fibre epoxy cross-ply laminates Pavizi, A. and Bailey, J.E. Journal of Materials Science Vol 13 (1978) pp 2131-2136 An investigation has been made of multiple transverse cracking in glass fibre/epoxy cross-ply laminates of differing transverse ply thickness, Transverse crack spacing was found to decrease with increasing applied stress and decreasing transverse ply thickness, which agrees well with a multiple cracking theory based on shear lag analysis. In these composites a small modulus change is observed at a strain lower than that at which cracking is initiated, associated with a visual, (and, under some circumstances, reversible) whitening effect,
COMPOSITES. JU LY 1979
The propagation of cracks in composites consisting of ductile wires in a brittle matrix Bowling, J. and Groves, G.W. Journal o f Materials Science Vol 14 (1979) pp 443-449 Using epoxy-resin fracture toughhess specimens reinforced with nickel wires, the critical stress intensity factor for propagation of unbridged cracks was shown to be greater for cracks arrested at fibres than for cracks in plain resin. Subsequent crack propagation can be explained in terms of the loads carried by bridging wires" undergoing debonding and pull-out,
Bright, P.F., Crowson, R.J. and Falkes, M.J. Journal of Materials Science Vol 13 (1978) pp 2497 - 2506 The pattern of fibre orientation in injection moulded strips of glass fibre-reinforced polypropylene has been studied using the technique of contact microradiography. High injection speed gives alignment of fibres transverse to the flow direction, while for very low speeds the fibres align parallel to the flow, resulting in a change of surface topography revealed in the scanning electron microscope. At low shear rates the fibres cause a significat increase in viscosity, but at shear rates likely to be encountered indus-
Statistical fatigue of graphite/epoxy angle-ply laminates in shear Yang, J.N. and Jones, D.L. Journal o f Composite Materials Vol 12 (October 1978) pp 371-389 A three-parameter fatigue and residual strength degradation model has been proposed to predict statistically the fatigue behaviour of composite laminae under axial shear loadings. The model is in good agreement with the results from an experimental test programme on g r a p h i t e / e p o x y ( + 45 °) two-ply laminates. Test results on the shear modulus degradation are also presented and a model for this is discussed.
trially the filled and unfilled melts have very similar viscosities.
The structure, modes of deformation and failure, and mechanical properties of diaminodiphenyl sulphonec u r e d t e t r a g ! y ci d y I 4, 4 ' diaminodiphenyl methane epoxy Morgan, R.J., O'Neal, J.E. and Miller, D.B. Journal of Materials Science Vol 14 (1979) pp 109-124 The tensile mechanical properties as a function of temperature and strain rate, are given for dds cured tgddm epoxies. The epoxies deform in tension by crazing, and shear banding which results in distinctive fracture topography. The epoxies containing a higher percentage of dds contain small c r y s t a l l i n e r e g i o n s of unreacted dds which can be eliminated during cure, leaving microvoids which act as stress concentrators and moisture sinks, A study of the effect of injection speed on fibre orientation in simple mouldings of short glass fibre-filled polypropylene
The thermal expansion of carbon fibre-reinforced plastics. Part 3: The influence of resin type Phillips, L.N. et al.JournalofMaterials Science Vol 13 (1978) pp 2217 -2225 Interferometric measurements of the linear thermal expansion coefficients, between 90K and 500K, are reported for pure Code 69 resin, Code 69 reinforced with unidirectional Courtaulds HTS carbon fibre, Code 69 reinforced with bidirectional HTS and DLS351/BF3400 reinforced with bidirectional HTS. A detailed knowledge of the temperature dependence of the thermal expansion characteristics of a resin permits a good estimate of the corresponding behaviour of unidirectional and bidirectional composites.
The thermal expansion of carbon fibre reinforced plastics. Part 4: Ply muitidirectlonai effects Phillips, L.N. et al Journal of Materials Science Vol 13 (1978) pp 2226 - 2232 Measurements of the principal linear thermal expansion coefficients of a tridirectional (-45 °, 0, +45 °) carbon fibre-reinforced plastics laminate are reported in the approximate temperature range 90K to 500K. The results are cornpared to expectations based on unidirectional and bidirectional laminates and some effects peculiar to multidirectional laminates are discussed.
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Mechnical properties of aramid fibre.reinforced acrylic bone cement Wright, T.H. and Trent, P.S.Journal of Materials Science Vol 14 (1979) pp 503-505 In a significant number of cases, prostheses attached to bone with polymethylmethacrylate cement, have had to be removed due to cracking in the cement. The modulus, tensile strength, and fracture toughness of a range of aramid reinforced cements are presented, and compared with similar attempts to reinforce with carbon and metal fibres. Significant enhancement of properties is possible with the addition of low volume fractions of fibre, without modification of the cornmonly used mixing technique. Microscopy of failure mechanisms in filament-wound pipe Jones, M.C.C. and Hull, D. Journal of Materials Science Vol 14 (1979) pp 165-174) Unlined filament-wound grp pipes generally fail under internal pressurization by weepage through microcracking before their ultimate burst strength can be realized. Whitening of the pipes under load can be correlated with different types of cracking which can be predicted from the stress state in the tube wall. These cracking mechanisms have been investigated by optical microscopy, and the development of a weepage path is described, On multiple transverse cracking in glass fibre epoxy cross-ply laminates Pavizi, A. and Bailey, J.E. Journal of Materials Science Vol 13 (1978) pp 2131-2136 An investigation has been made of multiple transverse cracking in glass fibre/epoxy cross-ply laminates of differing transverse ply thickness, Transverse crack spacing was found to decrease with increasing applied stress and decreasing transverse ply thickness, which agrees well with a multiple cracking theory based on shear lag analysis. In these composites a small modulus change is observed at a strain lower than that at which cracking is initiated, associated with a visual, (and, under some circumstances, reversible) whitening effect,
COMPOSITES. JU LY 1979
The propagation of cracks in composites consisting of ductile wires in a brittle matrix Bowling, J. and Groves, G.W. Journal o f Materials Science Vol 14 (1979) pp 443-449 Using epoxy-resin fracture toughhess specimens reinforced with nickel wires, the critical stress intensity factor for propagation of unbridged cracks was shown to be greater for cracks arrested at fibres than for cracks in plain resin. Subsequent crack propagation can be explained in terms of the loads carried by bridging wires" undergoing debonding and pull-out,
Bright, P.F., Crowson, R.J. and Falkes, M.J. Journal of Materials Science Vol 13 (1978) pp 2497 - 2506 The pattern of fibre orientation in injection moulded strips of glass fibre-reinforced polypropylene has been studied using the technique of contact microradiography. High injection speed gives alignment of fibres transverse to the flow direction, while for very low speeds the fibres align parallel to the flow, resulting in a change of surface topography revealed in the scanning electron microscope. At low shear rates the fibres cause a significat increase in viscosity, but at shear rates likely to be encountered indus-
Statistical fatigue of graphite/epoxy angle-ply laminates in shear Yang, J.N. and Jones, D.L. Journal o f Composite Materials Vol 12 (October 1978) pp 371-389 A three-parameter fatigue and residual strength degradation model has been proposed to predict statistically the fatigue behaviour of composite laminae under axial shear loadings. The model is in good agreement with the results from an experimental test programme on g r a p h i t e / e p o x y ( + 45 °) two-ply laminates. Test results on the shear modulus degradation are also presented and a model for this is discussed.
trially the filled and unfilled melts have very similar viscosities.
The structure, modes of deformation and failure, and mechanical properties of diaminodiphenyl sulphonec u r e d t e t r a g ! y ci d y I 4, 4 ' diaminodiphenyl methane epoxy Morgan, R.J., O'Neal, J.E. and Miller, D.B. Journal of Materials Science Vol 14 (1979) pp 109-124 The tensile mechanical properties as a function of temperature and strain rate, are given for dds cured tgddm epoxies. The epoxies deform in tension by crazing, and shear banding which results in distinctive fracture topography. The epoxies containing a higher percentage of dds contain small c r y s t a l l i n e r e g i o n s of unreacted dds which can be eliminated during cure, leaving microvoids which act as stress concentrators and moisture sinks, A study of the effect of injection speed on fibre orientation in simple mouldings of short glass fibre-filled polypropylene
The thermal expansion of carbon fibre-reinforced plastics. Part 3: The influence of resin type Phillips, L.N. et al.JournalofMaterials Science Vol 13 (1978) pp 2217 -2225 Interferometric measurements of the linear thermal expansion coefficients, between 90K and 500K, are reported for pure Code 69 resin, Code 69 reinforced with unidirectional Courtaulds HTS carbon fibre, Code 69 reinforced with bidirectional HTS and DLS351/BF3400 reinforced with bidirectional HTS. A detailed knowledge of the temperature dependence of the thermal expansion characteristics of a resin permits a good estimate of the corresponding behaviour of unidirectional and bidirectional composites.
The thermal expansion of carbon fibre reinforced plastics. Part 4: Ply muitidirectlonai effects Phillips, L.N. et al Journal of Materials Science Vol 13 (1978) pp 2226 - 2232 Measurements of the principal linear thermal expansion coefficients of a tridirectional (-45 °, 0, +45 °) carbon fibre-reinforced plastics laminate are reported in the approximate temperature range 90K to 500K. The results are cornpared to expectations based on unidirectional and bidirectional laminates and some effects peculiar to multidirectional laminates are discussed.
183