Region-dependent micro damage of enamel under indentation  

作　　者：Bing-Bing An Rao-Rao Wang .Dong-Sheng Zhang Rao-Rao Wang Dong-Sheng Zhang 

机构地区：[1]Shanghai Institute of Applied Mathematics and Mechanics,200072 Shanghai, China [2]The Tenth People's Hospital of Tongji University,200072 Shanghai, China [3]Department of Mechanics, Shanghai University,200444 Shanghai, China [4]Shanghai Key Laboratory of Mechanics in Energy Engineering,200072 Shanghai, China

出　　处：《Acta Mechanica Sinica》2012年第6期1651-1658,共8页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(11172161);the Science and Technology Commission of Shanghai Municipality(10410701900,11195820900 and 10ZR1423400);the Innovation Program of Shanghai Municipal Education Commission(12ZZ092);the State Key Laboratory of Oral Diseases(Sichuan University)(SKLODSCU2009KF03);the Shanghai Leading Academic Discipline Project(S30106)

摘　　要：The objective of this investigation is to explore the region-dependent damage behavior of enamel, as well as to develop a good understanding of the deformation mech- anisms of enamel with numerical modeling. Nanoinden- tation experiments have been performed to investigate the load-penetration depth responses for outer and inner enamel. Results show that the unloading curve does not follow the loading curve, and degradation of stiffness in the unloading curve is observed. Based on the experimental data, a physi- cal quantity, the chain density in protein, has been introduced to the Drucker-Prager plastic model. Numerical simulations show that the simulated load-penetration depth curves agree with the experiments, and the stiffness degradation behav- iors of outer and inner enamel are captured by the numerical model. The region-dependent damage behavior of enamel could be revealed by the numerical model. The micro dam- age affected area at inner enamel is larger than that at outer enamel, indicating that the inner enamel experiences more micro damage than the outer one. Compared with its outer counterpart, the inner enamel which is rich in organic protein could break more internal protein chains to dissipate energy and to enhance its resistance to fracture accordingly.The objective of this investigation is to explore the region-dependent damage behavior of enamel, as well as to develop a good understanding of the deformation mech- anisms of enamel with numerical modeling. Nanoinden- tation experiments have been performed to investigate the load-penetration depth responses for outer and inner enamel. Results show that the unloading curve does not follow the loading curve, and degradation of stiffness in the unloading curve is observed. Based on the experimental data, a physi- cal quantity, the chain density in protein, has been introduced to the Drucker-Prager plastic model. Numerical simulations show that the simulated load-penetration depth curves agree with the experiments, and the stiffness degradation behav- iors of outer and inner enamel are captured by the numerical model. The region-dependent damage behavior of enamel could be revealed by the numerical model. The micro dam- age affected area at inner enamel is larger than that at outer enamel, indicating that the inner enamel experiences more micro damage than the outer one. Compared with its outer counterpart, the inner enamel which is rich in organic protein could break more internal protein chains to dissipate energy and to enhance its resistance to fracture accordingly.

关 键 词：Enamel. Nanoindentation Damage. Numerical simulation 

分 类 号：TQ173.1[化学工程—搪瓷工业]