Strength, elasticity and the limits of energy dissipation in two related sea urchin spines with biomimetic potential

The calcitic spines of the sea urchins Heterocentrotus mamillatus and H. trigonarius are promising
role models for lightweight applications, bone tissue scaffolds and energy dissipating processes due
to their highly porous and organized structure. Therefore, mechanical properties including Young ’s
Modulus, strength, failure behaviour and energy dissipation efficiency have been investigated in
depth with uniaxial compression experiments, 3-point bending tests and resonance frequency damping
analysis. It was found that despite a very similar structure, H. trigonarius has a significantly
lower porosity than H. mamillatus leading to a higher strength and Young ’s Moduli, but limited
ability to dissipate energy. In order to show reliable energy dissipation during failure in uniaxial
compression, a transition porosity of 0.55 –0.6 needs to be exceeded. The most effective structure
for this purpose is a homogeneous, foam-like structure confined by a thin and d...

Source: Bioinspiration and Biomimetics - December 19, 2018 Category: Science Authors: Christoph Lauer, Kilian Sillmann, Sebastian Hau ßmann and Klaus G Nickel Source Type: research