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A strain gauge method for determining the mechanical properties of filaments
ponents. Transient wave propagation solutions are obtained numerically and are compared with essentially exact data in order to assess the accuracy and computation economy of tile model. An LVDT extensometer for tensile
studies of composite materials De Vekey, R. C. Journal of Materials Science, Vol 9, No 11 (Nov 1974) pp 1898-1900 A description of an economical, adaptable, high sensitivity extensometer system based on dc/dc linear variable, differential transformer (LVDT) transducers, with the oscillator and detector circuits built into the transducer body. The unit described is designed to monitor the faces of glass fibre reinforced cement specimens with nominal cross-section dimensions of 50 mm x 10 mm in a uniaxial tensile tests. It has also been used successfully for other similar materials and specimen sizes. A micromechanical analysis of crack propagation in an elastoplastic composite material Adams, D. F. Fibre Science and Technology, Vol 7, No 4 (October 1974) p 237 The initiation and subsequent crack propagation stages in a filamentreinforced composite lamina loaded in a transverse direction are modelled mathematically. The micromechanical approach is used to study the transverse properties in an individual lamina principally because these may be the property controlling features of a composite which may appear to be isotropic on the macroscopic scale. The analytical method incorporates the Prandtl-Reuss flow rule and the finite element method in an attempt to understand material behaviour under high stress gradients with local yielding conditions.
gradients due to the interaction of the vertical and horizontal displacements is noted.
ings is possible and the process is thought to have applications in the furniture industry.
On Young's modulus of short fibre
composites
A strain gauge method for determining the mechanical properties of filaments
Fukuda, H. and Kawata, K. Fibre Science and Technology, Vol 7, No 3 (Ju(v 1974) p 207 From an analysis of the mechanism of load transfer from matrix to fibre in a single short fibre model, the values of the Young's modulus of several composites are calculated and shown to be in good agreement with experimental data. It is pointed out that negligible interaction of the fibres is assumed and that three dimensional analysis is required to translate from the plane stress condition considered in this paper to the real materials encountered in practice.
Swearengen, J. C. and Eriksen, R. It. Journal of Testing and Evaluation, Fol 2, No 6 (Nov 1974) pp 546-550 A test method described permits the utilization of strain gauges to obtain mechanical properties of filaments. Uniaxial monotonic load/strain and creep measurements were made using general techniques to verify that the method measured properties representative of the filament. This method eliminates the need to obtain a compliance calibration for the testing machine and facilitates the measurement of small strains in filaments having very high stiffness values.
Post-buckling analysis of beams with transverse shear strains Tabaddor, F. Fibre Science and Technology, Vol 7, No 4 (October 1974) p 311
METAL MA TRICES
In this mathematical analysis it is pointed out that since most directionally reinforced composites have low rigidity compared with their axial stiffiaess, transverse shear deformation cannot be neglected. It is shown that the main effect of transverse shear strains is to reduce the loads at which initial buckling occurs.
Processing of high-reactivity epoxy resin moulding materials by screw injection moulding Staheli, T. Kunstoffe, Vol 64 (June 19 74) p 308 It has been shown that factors such as storage, stability, granulometry, plasticising behaviour in the screw and flow/hardness properties are all influential in screw injection moulding of epoxy resins. The various ways in which the processing is affected are described in detail.
The non-linear response of a fibre reinforced thin plate under dynamic loading Benveniste, Y. and Aboudi, J. Fibre Science and Technology, Vol 7, No 3 (Jul 19 74) p 223
Pulp forming techniques interest the furniture industry Editorial. Woodworking Industry (Nov 1974)p 12
The dunamic response of a unidirectionally fibre-reinforced thin plate is analysed mathematically and nonlinear behaviour is compared with that of a correspondingly anisotropic linear plate. Results are obtained for both normal and shear loading to show the effects of fibre orientation and the complex nature of the displacement
Wood pulp from softwood is mixed with long fibre Kraft pulp and suspended in water at a ratio of 99.3% water to 0.7% pulp, with a small percentage of resin additives. Components, mainly for the motor industry are present, are formed by hot die pressing this mixture after a vacuum dewatering stage. A variety of surfac-
COMPOSITES. JULY 1975
About optimization of the elastic deformation range by prestraining of a unidirectional composite material Shorshorov, M. K., Ustinov, L. M. and Kuznetzov, Y. G. Metallurgical Trans-
actions, Vol 5, No 9 (Sep 19 74) pp 2113 -2115 Two points are raised regarding a previous paper (Heckel et al, Met Trans, Vol 3 (1972) p 2507; abstract in Composites, Vol 4, No 2, p 92) in which a theoretical analysis was made of the effects of prestraining a fibre reinforced metal matrix composite. In their reply, the authors of the original paper show that the main conclusions of their paper are not affected but that the points raised provide a valuable complement to the original work.
Cast bonding produces quality metallic composites Kura, J. G. Materials Engineering, Vo180, No 5 (Oct 1974) p 60 A process for producing metal composites by casting liquid metal against preheated solid metal is described and it is claimed that dimensional accuracy approaching that of investment casting may be attained. Applications of the process include the fabrication of an alternator rotor with steel pole pieces in Inconel 713LC and the continuous production of copper clad steel wire.
Improvement in the stress-rupture strength of directionally solidified COTAC-type composites through
185
studies of composite materials De Vekey, R. C. Journal of Materials Science, Vol 9, No 11 (Nov 1974) pp 1898-1900 A description of an economical, adaptable, high sensitivity extensometer system based on dc/dc linear variable, differential transformer (LVDT) transducers, with the oscillator and detector circuits built into the transducer body. The unit described is designed to monitor the faces of glass fibre reinforced cement specimens with nominal cross-section dimensions of 50 mm x 10 mm in a uniaxial tensile tests. It has also been used successfully for other similar materials and specimen sizes. A micromechanical analysis of crack propagation in an elastoplastic composite material Adams, D. F. Fibre Science and Technology, Vol 7, No 4 (October 1974) p 237 The initiation and subsequent crack propagation stages in a filamentreinforced composite lamina loaded in a transverse direction are modelled mathematically. The micromechanical approach is used to study the transverse properties in an individual lamina principally because these may be the property controlling features of a composite which may appear to be isotropic on the macroscopic scale. The analytical method incorporates the Prandtl-Reuss flow rule and the finite element method in an attempt to understand material behaviour under high stress gradients with local yielding conditions.
gradients due to the interaction of the vertical and horizontal displacements is noted.
ings is possible and the process is thought to have applications in the furniture industry.
On Young's modulus of short fibre
composites
A strain gauge method for determining the mechanical properties of filaments
Fukuda, H. and Kawata, K. Fibre Science and Technology, Vol 7, No 3 (Ju(v 1974) p 207 From an analysis of the mechanism of load transfer from matrix to fibre in a single short fibre model, the values of the Young's modulus of several composites are calculated and shown to be in good agreement with experimental data. It is pointed out that negligible interaction of the fibres is assumed and that three dimensional analysis is required to translate from the plane stress condition considered in this paper to the real materials encountered in practice.
Swearengen, J. C. and Eriksen, R. It. Journal of Testing and Evaluation, Fol 2, No 6 (Nov 1974) pp 546-550 A test method described permits the utilization of strain gauges to obtain mechanical properties of filaments. Uniaxial monotonic load/strain and creep measurements were made using general techniques to verify that the method measured properties representative of the filament. This method eliminates the need to obtain a compliance calibration for the testing machine and facilitates the measurement of small strains in filaments having very high stiffness values.
Post-buckling analysis of beams with transverse shear strains Tabaddor, F. Fibre Science and Technology, Vol 7, No 4 (October 1974) p 311
METAL MA TRICES
In this mathematical analysis it is pointed out that since most directionally reinforced composites have low rigidity compared with their axial stiffiaess, transverse shear deformation cannot be neglected. It is shown that the main effect of transverse shear strains is to reduce the loads at which initial buckling occurs.
Processing of high-reactivity epoxy resin moulding materials by screw injection moulding Staheli, T. Kunstoffe, Vol 64 (June 19 74) p 308 It has been shown that factors such as storage, stability, granulometry, plasticising behaviour in the screw and flow/hardness properties are all influential in screw injection moulding of epoxy resins. The various ways in which the processing is affected are described in detail.
The non-linear response of a fibre reinforced thin plate under dynamic loading Benveniste, Y. and Aboudi, J. Fibre Science and Technology, Vol 7, No 3 (Jul 19 74) p 223
Pulp forming techniques interest the furniture industry Editorial. Woodworking Industry (Nov 1974)p 12
The dunamic response of a unidirectionally fibre-reinforced thin plate is analysed mathematically and nonlinear behaviour is compared with that of a correspondingly anisotropic linear plate. Results are obtained for both normal and shear loading to show the effects of fibre orientation and the complex nature of the displacement
Wood pulp from softwood is mixed with long fibre Kraft pulp and suspended in water at a ratio of 99.3% water to 0.7% pulp, with a small percentage of resin additives. Components, mainly for the motor industry are present, are formed by hot die pressing this mixture after a vacuum dewatering stage. A variety of surfac-
COMPOSITES. JULY 1975
About optimization of the elastic deformation range by prestraining of a unidirectional composite material Shorshorov, M. K., Ustinov, L. M. and Kuznetzov, Y. G. Metallurgical Trans-
actions, Vol 5, No 9 (Sep 19 74) pp 2113 -2115 Two points are raised regarding a previous paper (Heckel et al, Met Trans, Vol 3 (1972) p 2507; abstract in Composites, Vol 4, No 2, p 92) in which a theoretical analysis was made of the effects of prestraining a fibre reinforced metal matrix composite. In their reply, the authors of the original paper show that the main conclusions of their paper are not affected but that the points raised provide a valuable complement to the original work.
Cast bonding produces quality metallic composites Kura, J. G. Materials Engineering, Vo180, No 5 (Oct 1974) p 60 A process for producing metal composites by casting liquid metal against preheated solid metal is described and it is claimed that dimensional accuracy approaching that of investment casting may be attained. Applications of the process include the fabrication of an alternator rotor with steel pole pieces in Inconel 713LC and the continuous production of copper clad steel wire.
Improvement in the stress-rupture strength of directionally solidified COTAC-type composites through
185