Coconuts have thick shells, naturally designed to withstand a falls, protecting the seedling inside. According to a new study, the specialised structure of the coconut walls can be used to design buildings that can withstand earthquakes and other natural disasters.
The coconut has complex structure of three layers the outer brown, leathery exocarp, a fibrous mesocarp and a tough inner endocarp surrounding the pulp which contains the developing seedling.
Researchers at the University of Freiburg in Germany studied how the unique energy-absorbing properties of the coconut shell can be applied in architecture.
“By analysing the fracture behaviour of the samples and combining this with knowledge about the shell’s anatomy gained from microscopy and computed tomography, we aimed to identify mechanically relevant structures for energy absorption,” said researcher Stefanie Schmier.
The cells in the coconut’s endocarp layer have been found to possess a distinct, ladder-like design, which is believed help in withstand bending forces.
“The endocarp seems to dissipate energy via crack deflection” said Schmier. “This means that any newly developed cracks created by the impact don’t run directly through the hard shell,” she added.
According to the researchers this angular arrangement of cells help divert the trajectory of cracks. The longer a crack has to travel within the endocarp, the more likely it is to stop growing before it gets too big.
If textile fibres within concrete can be arranged similarly as the cells in a coconut, it might help buildings become stronger and able to withstand natural disasters.
“This combination of lightweight structuring with high energy dissipation capacity is of increasing interest to protect buildings against earthquakes, rock fall and other natural or manmade hazards,” says Schmier.
