| Summary: | 碩士 === 國立中正大學 === 機械工程所 === 98 === Most of the natural biomaterials have different functional optimized material structure ; hence , it would be meaningful to understand the secrets of nature and learn from nature to produce bio-inspired materials in the laboratory. Furthermore , the tiny change of material structure would detect the illness or environmental change . Only recently , with the development of nanoindentation instruments , it has been possible to investigate the size , shape and orientation of nanocrystalline microstructural constituent material of bio-hard tissue(such as tooth). Therefore , the mechanical analysis and modeling of nanostructured bio-composite become a very important research topic.
This research studies the mechanical behavior of enamel by finite element method. Using the basic mechanical theory of composite material to investigate mechanical problem of bio-tissue by creating different quantity of sheath models in micro-structural enamel. In the result , from micro-structural enamel models , the elastic modulus will be decreased as the quantities of the sheath increased. Secondly , calculating analytical solution of enamel rod model in two dimension was compared with finite element method to proof the correctness of analytical solution.Finally , in the stress analysis of micro-structural enamel , the quantity of sheath was no effect on the trend of stress distributing. It could find that the maxmum shear stress appeared on the interface of enamel rod and sheath , and the fracture would be generated in this place. No matter how the viscoelastic or elastic property of sheath , the stress distributing in the microstructure of enamel is similar.
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