Quasi-static and dynamic mechanical response of Strombus gigas (conch) shells

Quasi-static and dynamic compression and three-point bending tests have been carried out on Strombus gigas (conch) shells. The mechanical response is correlated with its microstructure and damage mechanisms. The mechanical response is found to vary significantly from specimen to specimen and requires the application of Weibull statistics in order to be quantitatively evaluated. The conch exhibited orientation dependence of strength as well as significant strain-rate sensitivity; the failure strength at loading rates between 10×103 and 25×103 GPa s−1 was approximately 50% higher than the quasi-static strength. Quasi-static compressive failure occurred gradually, in a mode sometimes described as ‘graceful failure’. Crack deflection, delocalization of damage, and viscoplastic deformation of the organic layers are the most important mechanisms contributing to the unique mechanical properties of these shells.