Strengthening the Mechanical Performance of Sea Urchin Skeleton by Tube Feet Pore

In this paper, the effects of tube feet pores on the mechanical properties of Sea Urchin Skeleton (SUS) have been studied. The pore structure of drop-like Tripnenstes gratilla (a sea urchin) skeleton is characterized by Scanning Electron Microscopy (SEM). Based upon the data, the finite element method has been employed to analyze the Maximum Tensile Stress (MTS) of SUS models with different pore positions, accompanied by compressive tests on SUS-like ceramics. Results indicate that for a drop-like SUS, the MTS keeps a linear relationship with the maximum load applied on the SUS. More importantly, the mechanical performances of some perforated SUSs are better than their non-perforated counterparts due to their lower MTS values, e.g . the maximum load can thus be increased by 35% when the pore is perforated at −10°. The strengthening is attributed to the introduced pore that causes the redistribution of stress and partly reduces the stress intensity on the original MTS position. By contrast, the pore only increases the MTS value of a spherical shell under isostatic pressure or unidirectional pressing. This is a strong hint that the drop-like shape of SUS has evolved to work with the tube feet pores to better protect their bodies.