Influence of Microstructure on Mechanical Properties of Limaria basilnica

Abstract

Shell was the simplest biological mineral material protecting the soft tissue. In this paper, the effects of the cross bedded structure of Limaria basilanica shell and organic matter on the three-point bending behavior of Limaria basilanica shell were studied. Experimental results showed that the mechanical properties of shell were closely related to its microstructure, and both of them had anisotropy. The mechanical properties and density of the shell decreased evidently with the increase of temperature. It was indicated that the organic matter in the shell decreased with the increase of heating temperature, which lead to a marked decrease in mechanical properties of Limaria basilanica. The bearing capacity of the shell in the vertical direction was higher than that of the shell in the horizontal direction. When the organic matter in the shell was removed, the three-point bending strength of the shell was only one- twenty or one-thirty of its original strength. The main toughening mechanisms of Limaria basilanica shell were crack deflection, fiber pull out, and viscoelastic properties of organic matter. The bionic study on the toughening mechanism of shell material provided important information about design of the composite materials.