Researchers Take Inspiration From Coconut Shells To Develop Earthquake Safe Structures

Researchers from the University of Freiburg's Plant Biomechanics Group are taking inspiration from a coconut to design buildings that can withstand earthquakes and other natural disasters.

A coconut palm tree can grow up to 30 metres tall. What's interesting to note is that even after falling from such a height the coconut remains intact and does not split into pieces, thus protecting the inner seed. This is due to the fact that the tropical fruit has a complex structure of three layers comprising of the outer brown, leathery exocarp, a fibrous mesocarp and a tough inner endocarp which contains the seeds, resting inside the pulp, reported Nature World News.

The researchers are now looking out for ways in which they can apply the specialized coconut structure in architecture. They have joined hands with civil engineers and material scientist to engineer buildings that can withstand the impact of natural disasters like earthquakes, according to Daily Mail.

In order to understand the mechanism behind the complex coconut wall structure, the research team used compression machines and an impact pendulum to check how the energy is distributed in the coconut layers.

According to the researchers, there is a ladder-like system within the inner endocarp layer which withstands strong bending forces. Cells in the endocarp layer are surrounded by several woodied rings joined together by parallel bridges that deflect the cracks.

It is believed that the angle of the vascular bundles helps divert the trajectory of the cracks. The longer the time a crack takes to travel within the endocarp, the more likely it is that it will stop before reaching the other side.

"The endocarp seems to dissipate energy via crack deflection," said plant biomechanist Stefanie Schmier in a statement. "This means that any newly developed cracks created by the impact don't run directly through the hard shell."

Experts believe that by applying the distinct angle of the vascular bundle to the arrangement of textile fibers within concrete could help create a super strong material that will enable crack deflection and prevent as much damage as possible during earthquakes.

"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," added Schmier.

The research study, which is part of the larger "Biological Design and Integrative Structures" project, was published in Society for Experimental Biology Annual Meeting 2016.