Influence of Solution Treatment, Sr-Modification and Short Fibre Reinforcement on the Eutectic Morphology of Al-Si Alloys

Noise attenuation is a key contemporary issue associated with the protection of human health. In this study, the possibilities of affecting acoustic properties of plaster composites by the addition of short-fibre reinforcement are described. The improvement of attenuation abilities was first verified using a simple numerical model with a pure plaster followed by using a reinforced plaster. The model results revealed a mutual correlation between the fibre ratio and dissipated acoustic energy. Hence, typical plasters used in the building industry (e.g., plaster, lime cement, and cement) are used as the base materials of the tested composites. The reinforcing dispersion in the form of short fibres (basalt and glass) with a defined length was selected after evidence from previously reported studies and after the comparison of some other fibres with respect to the trade-off between the rendered mechanical properties and cost. Transfer functions of the tested samples were measured using an impedance tube with two microphones, followed by the calculation of the total acoustic absorption. On the other hand, cement and plaster materials exhibited a low damping ability, and the absorption could be considerably increased by the addition of fibres, especially in the area around 1 kHz. In contrast, the UM plaster exhibited good damping properties even without the dispersion, and the addition of improper fibres such as glass ones possibly worsened the properties. The acoustic attenuation of the plaster composites can be improved by the appropriate combination of the base material and fibre dispersion. However, it is not possible to generalise this improvement for all possible combinations.

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Enhanced epoxy adhesion between steel plates by surface treatment and CNT/short-fibre reinforcement

Composites Science and Technology ◽

10.1016/j.compscitech.2016.03.008 ◽

2016 ◽

Vol 127 ◽

pp. 149-157 ◽

Cited By ~ 28

Author(s):

Binhua Wang ◽

Yuxuan Bai ◽

Xiaozhi Hu ◽

Pengmin Lu

Keyword(s):

Surface Treatment ◽

Steel Plates ◽

Short Fibre ◽

Fibre Reinforcement

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Short Fibre Polymer Composites: a Fracture-Based Theory of Fibre Reinforcement

Journal of Composite Materials ◽

10.1177/002199839402800701 ◽

1994 ◽

Vol 28 (7) ◽

pp. 588-606 ◽

Cited By ~ 57

Author(s):

Michael R. Piggott

Keyword(s):

Volume Fraction ◽

Force Balance ◽

Short Fibre ◽

Standard Theory ◽

Fibre Reinforcement ◽

Minimum Volume ◽

Stress Strain ◽

Reinforced Polymers ◽

Fibre Composites ◽

The Matrix

The interphase between reinforcing fibers and polymers is brittle, and does not behave in the way it was assumed to when the standard theory for composite strength was developed. Futhermore, this theory predicts curved stress-strain plots for aligned short fibre composites, yet the evidence for this is unconvincing, and there is much new evidence that these stress-strain curves are straight. The time has therefore come to abandon this approach and take into account, instead, the apparent brittleness and sudden failure of aligned fibre reinforced polymers. This paper presents the evidence, and introduces the new approach. This involves microcrack development in composites from stress concentrations at the fibre ends. Since such failure initiation can occur simultaneously at many sites, the stress required to cause abrupt failure across the whole cross section can be estimated by a simple force balance. This analysis gives the familiar expressions used for short fibre composites, with one important difference. For carbon reinforced polymers, the polymer has to reach its breaking strength before failure, so that there is no minimum volume fraction for reinforcement with these composites. With glass, on the other hand, which has a higher breaking strain than most thermosets used for composites, the matrix appears unable to exert its full strength. Thus low fibre volume fraction glass fibre composites can be weaker than the matrix, and a minimum volume fraction for reinforcement exists.

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