Introducing ductility in hybrid carbon fibre/self-reinforced composites through control of the damage mechanisms

Abstract

a b s t r a c tCarbon fibre composites possess excellent mechanical properties, but suffer from brittleness. Hybridisation with self-reinforced polypropylene (SRPP) is a promising strategy to introduce ductility into carbon fibre-reinforced polypropylene (CFRPP). The present work demonstrates how different damage mechanisms in these hybrid composites change as a function of the carbon fibre volume fraction, the directionality of CFRPP and SRPP and their relative layer thickness. Multiple fractures of the CFRPP layers or ''fragmentation'' is achieved by optimising these parameters. This leads to a ductile hybrid composite with a gradual failure development.

Combining fibre rotation and fragmentation to achieve pseudo-ductile CFRP laminates

“…These XCT images suggest that the [±26 4 /0] s specimens failed following the large delaminations that propagated from the initial fracture of the 0 • plies, meaning that limited, or no, fragmentations could develop. 5 /0] s specimens To investigate the development of damage over the course of the stress plateau observed in Figure ??, five [±26 5 /0] s specimens have been loaded to different points along the stress-strain graph as shown in Figure ??. Each was then removed from the test machine and submerged in zinc iodide dye penetrant.…”

The importance of bonding in intralayer carbon fibre/self-reinforced polypropylene hybrid composites

“…Hine et al [18] hybridised carbon fibres with polyamide fibres and achieved large ductility improvements in bending, but not in tension. Similarly, Taketa et al [13] and Swolfs et al [17,24] hybridised carbon fibres with self-reinforced polypropylene (SRPP). The 20% failure strain of SRPP provides a large potential for enlarging the ultimate failure strain of the hybrid composite.…”

The influence of the hybridisation configuration on the mechanical properties of hybrid self reinforced polyamide 12/carbon fibre composites

“…Following on from this study, Swolfs et al [2,3,28] looked at the same material combination, oriented polypropylene tapes and carbon fibres, but in this case in an intra-layer configuration. Here, an oriented polypropylene tape was co-woven with a carbon fibre/polypropylene prepreg tape to produce a co-woven cloth, which was then processed using the hot compaction process to produce hybrid composite sheets.…”

“…This trade-off between modulus and toughness, often called the modulus/toughness dilemma [1][2][3][4], continues to be a major area of research interest, with the continuing objective of developing so called 'hybrid' materials that could combine these two important properties. One popular route to hybridisation is to combine two different fibre types in a composite, often a high modulus but brittle fibre (usually carbon) and a ductile, and often lower modulus, polymeric fibre.…”