Bio-inspired design for enhanced damage tolerance of self-reinforced polypropylene/carbon fibre polypropylene hybrid composites

• Published in: Composites. Part A, Applied science and manufacturing Vol. 121; pp. 341 - 352
• Main Authors: Mencattelli, Lorenzo, Tang, Jun, Swolfs, Yentl, Gorbatikh, Larissa, Pinho, Silvestre T.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2019
• Subjects: A: Hybrid; B: Damage tolerance; B: Fracture toughness; D: Failure; A: Hybrid; B: Fracture toughness; D: Failure; B: Damage tolerance
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2019.03.028

In this work, we investigate the toughness of an inter-layer Self-Reinforced Polypropylene/Carbon Fibre Polypropylene (SRPP/CFPP) cross-ply hybrid composite and devise strategies to improve two aspects of its damage tolerance: (i) increasing the energy dissipation capability and (ii) enhancing the impact damage tolerance. To this end, we introduced discontinuities in the form of laser-cuts across the fibres of the CFPP plies, tailoring two patterns of laser-cuts to meet each specific damage tolerance requirement. We conducted penetration impact and Double Edge Notched Tensile (DEN-T) tests. The DEN-T tests, analysed via the Essential Work of Fracture method, show that engineering the microstructure successfully diffused damage. This resulted in a great increase in energy dissipation capability — 90% higher than a reference non-engineered structure. Engineering the microstructure of impact samples has led to enhanced impact damage tolerance with increased energy dissipation at a sub-critical level and delayed critical failure.