Forgot your password?
New user?
New Window Opens on the Secret Life of Microbes: Scientists Develop First Microbial Profiles of Ecosystems
CAS announces the release of SciFinder Scholar for Mac OS X
Press Releases
Press Releases
| Check out our New Publishers' Select for Free Articles |
Applied Composite Materials: An International Journal for the Science and Application of Composite Materials (v.5, #4)
Alternative Uses of Waste Glasses: Issues on the Fabrication of Metal Fibre Reinforced Glass Matrix Composites by P. A. Trusty; A. R. Boccaccini (pp. 207-222).
In order to investigate a potential use for recycled speciality glasses (specifically those containing hazardous elements), a processing route has been developed for the fabrication of metallic fibre mat reinforced glass matrix composites. Commercially available 3-dimensional stainless steel 316L fibre mats were used as the metal reinforcement, and a borosilicate glass which had been used previously in radiation experiments was used as the glass matrix. The fibre mats were infiltrated with a commercially available silica sol using electrophoretic deposition (EPD), and the glass matrix was laid in between infiltrated fibre mats prior to consolidation using uniaxial cold pressing. It was found that composites with sufficient integrity could be obtained from this recycled waste glass after sintering in air at 850°C for 1 h. The deposited silica remained amorphous at the processing temperature, providing a porous interface between the metallic reinforcement and the waste glass matrix. The processing issues involved in composite fabrication, namely, the EPD infiltration parameters for the silica sol, the quantity and subsequent effect of the impurities present in the waste glass, and the densification of the composite material on sintering, have been discussed.
Keywords: recycling; waste glass; composites; metal fibre reinforcement; electrophoretic deposition
Design of Fibre Reinforced Composite Structures Subjected to High Strain Rates Using Finite Element Analysis by N. M. S. Al-Bastaki (pp. 223-236).
A finite element analysis of fibre reinforced plastic tubes subjected to a dynamic internal pressure pulse is performed using the ABAQUS finite element program. The effects of strain rate on the ply properties, the nonlinearity of the stress-strain curves, failure and post-failure theories are incorporated in the analysis. The results of the analysis show good agreement with the experimental stress-strain and strain-time results for 45° and 65° Kevlar fibre reinforced epoxy (KRP) tubes.
Keywords: filament wound tube; KRP; ply properties; nonlinear behaviour; progressive failure; strain rate effects; finite element analysis; general shell element; dynamic analysis
Finite Element Assisted Modelling of the Microscopic Impregnation Process in Thermoplastic Preforms by S. M. Haffner; K. Friedrich; P. J. Hogg; J. J. C. Busfield (pp. 237-255).
Fibre reinforced composite materials incorporating thermoplastic matrices are gaining increasing popularity in many industrial applications. One of the potential preforms for the manufacture of technical components is commingled yarn composed of reinforcement and matrix in fibre form. These are often employed in the pultrusion process. Another innovative preform consists of polymer powder preimpregnated sheath surrounding fibre bundles. To achieve adequate mechanical properties of the final product it is essential, when producing laminates by a process such as pultrusion with both types of preform, that sufficient matrix impregnation is achieved. The prevention of voids and dry-spots in the laminate requires a theoretical understanding of the mechanisms involved. On a microscopic scale, several finite element (FE) models can be used to simulate the progress of the matrix flow into the interstitial spaces between the single reinforcement fibres. In the present simulations, a hexagonal and a square arrangement account for two of the various fibre packings occurring in a laminate. It permits an estimation of the impregnation performance of commingled and powder impregnated yarns. For each preform the shear rate, to which the polymer matrix is subjected during the impregnation and consolidation process, can be predicted.
Keywords: composites; pultrusion; fibre impregnation; finite element simulation
Modelling of the Mechanical Properties of Composite Materials at High Temperatures. Part 3. Textile Composites by Yury Dimitrienko (pp. 257-272).
The present paper is devoted to extending the model suggested previously (Dimitrienko, 1997) to textile composite materials at high temperatures. The model describes a degradation of elastic moduli of polymer-matrix composites in heating to high temperatures (2000°C). With the help of the model, analytical relations between elastic moduli of textile composites and elastic characteristics of their matrices and fibres, as well as geometrical structural parameters of the composites at high temperatures have been derived. Calculated results have been compared with experimental data for carbon/ and glass/phenolic composites as examples. Heat expansion and shrinkage of the composites in heating up to high temperatures have been also considered.
Keywords: textile composite; high temperatures; elastic moduli; heat expansion; shrinkage