Hybrid composites based on polyethylene and carbon fibres. Part 6: Tensile and fatigue behaviour

The tensile and fatigue behaviour of unidirectional carbon-high-performance polyethylene/epoxy hybrid composites has been studied, including the effect of hybrid design and surface treatment of the high-performance polyethylene ( ) fibres. Results indicated that the tensile behaviour of carbon- hybrids in both monotonic and fatigue testing can be interpreted, adopting the conventional ‘constant strain’ model for hybrid composites. Deviations from this constant strain model, so-called hybrid effects, were observed in monotonic tensile testing for those hybrid systems with the highest degree of fibre dispersion, incorporating either untreated or treated fibres, whereas only the latter displayed synergistic fatigue performance. Hybrid effects under tensile loading conditions were in reasonable agreement with calculations accounting for statistical effects and stress concentrations as determined by finite element analyses