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

Quasi-static and dynamic compression and three-point bending tests have bee n carried out on Strombus gigas (conch) shells. The mechanical response is correlated with its microstructure and damage mechanisms. The mechanical re sponse is found to vary significantly from specimen to specimen and require s the application of Weibull statistics in order to be quantitatively evalu ated. The conch exhibited orientation dependence of strength as well as sig nificant strain-rate sensitivity; the failure strength at loading rates bet ween 10 x 10(3) and 25 x 10(3) GPa s(-1) was approximately 50% higher than the quasi-static strength. Quasi-static compressive failure occurred gradua lly, in a mode sometimes described as 'graceful failure'. Crack deflection, delocalization of damage, and viscoplastic deformation of the organic laye rs are the most important mechanisms contributing to the unique mechanical properties of these shells. (C) 2001 Elsevier Science B.V. All rights reser ved.