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Failure mechanism of a brittle layered material

Wang, Rentong
http://rave.ohiolink.edu/etdc/view?acc_num=osu1086210643

Abstract Details

2004, Doctor of Philosophy, Ohio State University, Mechanical Engineering.
Layered structures have been widely used in industrial and military applications to protect substrates from environmental effects. The same strategy has been applied to medical implants and various dental restorations such as complete and partial veneering of teeth with ceramics to protect the remaining tooth structure. We experimentally and theoretically investigate the failure mechanisms of a simple brittle layered structure subjected to a static indentation load. For this problem, cracks were observed to initiate from either the top or the bottom surface of the top layer depending on the top layer thickness, the material properties of the layers, and the indenter size. In order to model the experimentally observed variation of critical indentation load, a statistical theory with flaw distribution in brittle specimens is employed. First, we examined an existing fracture mechanics based statistical theory. We pointed out the premature use of infinitesimally small volumetric element assumption in the theoretical derivation of the failure probability prediction formula and proposed an alternative form of prediction formula. Second, using indentation tests on monolithic materials we test the hypothesis that the failure probability model developed by Fischer-Cripps and Collins (1994) can be used without introducing an empirically derived parameter and therefore can serve as a predictive tool for a cone crack imitation in a monolithic solid. Third, the above methods are modified to a layered structure, and multi-axial stress states of indentation is taken into account in the failure probability analysis. Two modes of failures, a Hertzian cone crack initiating from the contacting surface and a half-penny-shaped crack initiating from the interface, are theoretically predicted and compared with experimental data. Fourth, a finite half-penny-shaped crack perpendicular to the interfacial surface was introduced at the bottom surface of the top layer. The effect of interfacial debonding on the Stress Intensity Factor is examined. The above study provides some insights into better designing and handling of the crown structures in the dental restoration applications.
Noriko Katsube (Advisor)
134 p.
Applied Mechanics
Layered Material; Indentation; Failure Probability

Recommended Citations

Citations

  • Wang, R. (2004). Failure mechanism of a brittle layered material [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1086210643

    APA Style (7th edition)

  • Wang, Rentong. Failure mechanism of a brittle layered material. 2004. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1086210643.

    MLA Style (8th edition)

  • Wang, Rentong. "Failure mechanism of a brittle layered material." Doctoral dissertation, Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1086210643

    Chicago Manual of Style (17th edition)

osu1086210643
1,344
© 2004, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.
Release 3.2.12