PSI - Issue 28

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Author name / Structural Integrity Procedia 00 (2019) 000–000

M.P. Silva et al. / Procedia Structural Integrity 28 (2020) 2235–2244

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Figure 7 - Residual tensile strength versus impact energy for all laminates at different impact energies.

The introduction of glass fibre into composite changed the damage mode and increase the impact resistance of the laminate. It is possible to conclude that impact resistance shows to be very dependent on the type of fibres and their configuration thru thickness. 4. Conclusions Low velocity impact response of flax composite and hybrid flax/glass fibre composite was studied. The hybridization by the introduction of glass fibre (4 and 6 layers) were used in order to improve the impact resistance of the composite. The maximum impact load, for 11 J increases of 75.2 % and 178 % from flax laminate to 1x hybrid and 2x hybrid, respectively. Regarding to displacement, opposite behaviour occurs, a decrease of around 46 % and 58.4 % respectively to 1x hybrid and 2 x hybrid laminates. In terms of elastic recuperation, the hybridization proves to be a good solution, hybrid composites tend to absorb less energy and for instance increase the elastic energy when compared with simple flax composites. Finally, it was observed that the residual strength is higher for hybrid composites which represent a overall increase of the mechanical properties of the composite. Acknowledgements This work was supported by the project Centro-01-0145-FEDER-000017 - EMaDeS - Energy, Materials and Sustainable Development, co-financed by the Portugal 2020 Program (PT 2020), within the Regional Operational Program of the Center (CENTRO 2020) and the European Union through the European Regional Development Fund (ERDF). References

Aktaş, Mehmet, Cesim Atas, Bülent Murat İçten, and Ramazan Karakuzu. 2009. 'An experimental investigation of the impact response of composite laminates', Composite Structures, 87: 307-13.