Fracture mechanics of mollusc shells
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Date
2005-11-27
Authors
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Journal ISSN
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Publisher
The Bragg Institute, Australian Nuclear Science and Technology Organisation
Abstract
The shape and structure of the shells of molluscs has attracted considerable attention. One aspect of interest is the comparatively high resistance to fracture of these shells. It is known that they are composite structures of aragonite, other calcereous materials, and up to 5% by volume of protein ‘glue’. A large component of their toughening derives from crack tip blunting, deflection and closure, concepts well-known from the field of fracture mechanics. However, the possibility that they might also derive a measure of toughening from a residual stress distribution has been generally overlooked, although Illert first raised this over a decade ago. The optimum situation would be when the inner surface of the shell is maintained in a state of tensile stress, while the outer layers are in the necessarily counter-balancing compressive state. We have examined this hypothesis using a combination of neutron diffraction and scanning electron microscopy and find that it is certainly feasible. However, a definitive proof will require a diffraction study. © The Authors
Description
Physical copy held by ANSTO Library at DDC 539.7217/2
Keywords
Molluscs, Diffraction, Electron microscopy, Invertebrates, Fracture mechanics, Microscopy, Minerals, Scattering, Residual stresses
Citation
Cortie, M. B., McBean, K. E., & Elcombe, M. M. (2005). Fracture mechanics of mollusc shells. Paper presented at the Eighth International Conference on Neutron Scattering ICNS 2005: "Neutrons for structure and dynamics - a new era", Sydney Convention & Exhibition Centre, Sydney, Australia, 27 November-2 December 2005. In Final Programme and Abstract Book, (pp. 244).