Tensile failure of hybrid composites: measuring, predicting and understanding

Yentl Swolfs,Ignaas Verpoest,Larissa Gorbatikh

doi:10.1088/1757-899x/139/1/012008

Yentl Swolfs, Ignaas Verpoest + Show 1 more

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https://doi.org/10.1088/1757-899x/139/1/012008

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Abstract

Fibre-hybrid composites are attracting an ever-increasing interest from academia and industry. It is therefore vital to develop a solid understanding of their basic mechanical properties. Measuring and predicting the tensile failure of hybrid composites however remains a challenging task. This paper describes how failure develops in unidirectional (UD) hybrid composites, and how this can be predicted using fibre break models. It also provides recommendations for experimental measurements of the hybrid effect, which is a synergetic increase of the failure strain of low elongation fibres when hybridised with higher elongation fibres. Finally, limitations of our understanding of the tensile failure of hybrid composites are discussed and recommendations for future research are proposed.

Highlights

Fibre-reinforced polymer composites are composed of fibres in a polymeric matrix
This paper describes how failure develops in unidirectional (UD) hybrid composites, and how this can be predicted using fibre break models
It provides recommendations for experimental measurements of the hybrid effect, which is a synergetic increase of the failure strain of low elongation fibres when hybridised with higher elongation fibres

Summary

Introduction

Fibre-reinforced polymer composites are composed of fibres in a polymeric matrix. The fibres impart stiffness and strength, whereas the matrix provides structural integrity. Carbon/glass hybrids were initially developed to reduce the cost of carbon fibre components in the sixties [4] This triggered a large body of research in the seventies and the eighties [5,6,7,8,9,10,11,12] to explore their mechanical properties. The typical stress-strain diagram of a hybrid composite (see Figure 1) shows two distinct peaks, which are associated with failure of the low (carbon) and high elongation (glass) fibres respectively. The transition between these two peaks can be sharp as, or can consist of a plateau [13] The transition between these two peaks can be sharp as in Figure 1, or can consist of a plateau [13]

Positive hybrid effect

Hybrid effect

Findings

Experiments Model