Matrix-fiber stress transfer in composite materials: Elasto-plastic model with an interphase layer

A theory is presented for the mechanical behaviour of fibre-reinforced composite materials at large strains. It is based on the distribution of fibres within the material and uses only basic mechanical properties of the fibres and matrix. The angular distribution of fibres is described by an orientation distribution function, g ( θ, ϕ ), which changes as the material is stretched, becoming greater along the directions of greatest tensile strain. No assumption is made about stress transfer to the fibres, or their length, except that they are long enough for this to happen effectively. The analysis predicts the reorientation of the fibres with strain and shows good agreement with preliminary experimental results from spinal ligaments. The predicted stress-strain behaviour shows qualitative agreement with experiment but further analysis is needed to take account of the crimping of the collagen fibres which occurs in this material. The theory may also have application to reorientation effects observed in drawn polymers and this is demonstrated with reference to polyethylene and polyethylene terephthalate.

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Influence of Fibre Taper on the Interfacial Shear Stress in Fibre-Reinforced Composite Materials during Elastic Stress Transfer

Composite Interfaces ◽

10.1163/092764409x12580201111665 ◽

2010 ◽

Vol 17 (1) ◽

pp. 74-80 ◽

Cited By ~ 16

Author(s):

K. L. Goh ◽

J. R. Meakin ◽

D. W. L. Hukins

Keyword(s):

Shear Stress ◽

Composite Materials ◽

Elastic Stress ◽

Interfacial Shear Stress ◽

Stress Transfer ◽

Interfacial Shear ◽

Reinforced Composite

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A Study of the Effect of Acetylation and Propionylation on the Interface of Natural Fibre Biodegradable Composites

Advanced Composites Letters ◽

10.1177/096369350501400202 ◽

2005 ◽

Vol 14 (2) ◽

pp. 096369350501400 ◽

Cited By ~ 17

Author(s):

V. Tserki ◽

C. Panayiotou ◽

N. E. Zafeiropoulos

Keyword(s):

Composite Materials ◽

Negative Impact ◽

Fibre Composite ◽

Stress Transfer ◽

Natural Fibre ◽

Surface Treatments ◽

Biodegradable Composites ◽

Interface Surface ◽

Fibre Composites ◽

Materials Used

Composite materials are a class of materials used in many diverse applications. Very recently the attention has shifted to the development of green composites that are easily recycleable and in this case the use of biodegradable matrices and fibres appear to be highly attractive. In the present study a class of biodegradable polyesters are used as matrices to produce fully biodegradable composites, reinforced with lignocellulosic natural fibres. This new class of composites is fully biodegradable, but the key aspect that governs the behaviour of the composites remains the interface. Surface treatments, although having a negative impact on economics, may improve the compatibility and strengthen the interface in natural fibre composite materials. In the present study the effect of two surface treatments, namely acetylation and propionylation, upon the interface of natural fibre composites is assessed by means of fragmentation tests. It has been found that both treatments led to an improvement of the stress transfer efficiency at the interface, and both applied treatments were optimised, accordingly.

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