Fig. 5. Box plots of the mean fibre stress f at mini-composite failure for different nominal gauge lengths lg.
Fig. 6. Variation of the mean fibre stress f at mini-composite failure with matrix volume fraction 1 − ϕ for (a) 50 mm, (b) 125 mm and (c) 250 mm nominal gauge length.
The dashed trend lines represent least-squares fits to the scattered data.
reaches 0.19% at most, which is far lower than the 0.5% strainto-failure of the filaments [53].
These observations indicate that the mini-composites’ failure may be matrix-driven.
This assumption is further supported by the correlation of the fibre stress at mini-composite failure and the mini-composites’ matrix volume fraction: overall, the mean stress in the fibres at mini-composite failure decreases with increasing matrix volume fraction, as shown in Fig. 6.