Combination of biological mechanisms for a concept study of a fracture-tolerant bio-inspired ceramic composite material
| Autor: | Dietmar Koch, Heide Humburg, Eike Volkmann, Jörg Müssig |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Toughness
Materials science Mechanical Engineering Composite number Stiffness Epoxy bioinspired ceramics fracture toughness composite Cracking Fracture toughness Mechanics of Materials Deflection (engineering) visual_art visual_art.visual_art_medium medicine General Materials Science Ceramic medicine.symptom Composite material |
| Popis: | The biological materials nacre and wood are renowned for their impressive combination of toughness and strength. The key mechanisms of these highly complex structures are crack deflection at weak interfaces, crack bridging, functional gradients and reinforcing elements. These principles were applied to a more fracture-tolerant model material which combined porous stiff ceramic layers, manufactured by freeze casting, infiltrated and bonded by a polymer phase reinforced with fabric layers. In the hybrid composites, crack deflection occurred at the ceramic–fabric interface and the intact fabric layers served as crack-bridging elements. Fabric-reinforced epoxy layers stabilized the fracture behaviour and delayed catastrophic failure of the material. The influence of the different components was analysed by varying the ceramic, fabric and interface properties. More ductile fabrics lead to larger strain to failure and more crack bridging but reduced the composite strength and stiffness after initial cracking. Higher elastic mismatch between the components improved crack deflection and bridging but resulted in deterred load transfer and a lower strength. The stiffness and strength of the ceramic layers influenced the elastic properties of the laminar composite and the initial crack resistance. Flaw tolerance was increased with polymer infiltration. We show with our hybrid ceramic–fabric composite as a bio-inspired concept study how fracture toughness, work of fracture and tolerance for cracking can be tailored when the contributing factors, i.e. the ceramic, the fabric and their interface, are modified. |
| Databáze: | OpenAIRE |
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