Among the major groups of materials, some polymers and resins are limited in usage due to their brittleness. To date, we lack a comprehensive solution to overcome brittleness. Mimicking from biological structures made up of ceramics with excellent strength and flexibility can help us to find a solution to this problem. In this study, for the first time, we mimicked the structure of spicules in Euplectella aspergillum (EA) sponges and developed a novel structure to improve the mechanical properties of brittle rods. In the newly developed structure, cylinders with various diameters were printed by a 3D printer and then inserted into each other. The nested cylindrical structures (NCSs) with optimized mechanical properties had a cylinder wall thickness of 1.30 mm with a density of 1.27 ± 0.01 g/cm3 (approximately 8.6% less than that of solid rods (SRs)). The flexural strength, strain, modulus and toughness of SR were improved in the NCSs from 108.04 ± 11.30 MPa, 1.95 ± 0.20%, 3.98 ± 0.05 GPa and 1.42 ± 0.20 kJ/m3 to 168.45 ± 14.45 MPa, 4.10 ± 0.41%, 5.52 ± 0.05 GPa and 6.71 ± 0.80 kJ/m3, respectively. The NCSs showed a lower density as well as improved mechanical properties compared to SRs. According to the SEM observations, the dominant mechanisms on the toughening of NCSs with a cylinder wall thickness of 0.80 mm were crack branching, crack bridging, and crack deflection. However, for NCSs with a cylinder wall thickness of 1.00 and 1.30 mm the dominant mechanism was crack deflection. The results of this paper open a new horizon for designing new structures from brittle materials with higher strength and flexibility.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry