Computational and experimental study of instrumented indentation
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2005
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| Online Access: | http://hdl.handle.net/1721.1/16624 |
| _version_ | 1811098358917365760 |
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| author | Chollacoop, Nuwong, 1977- |
| author2 | Subra Suresh. |
| author_facet | Subra Suresh. Chollacoop, Nuwong, 1977- |
| author_sort | Chollacoop, Nuwong, 1977- |
| collection | MIT |
| description | Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004. |
| first_indexed | 2024-09-23T17:13:50Z |
| format | Thesis |
| id | mit-1721.1/16624 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T17:13:50Z |
| publishDate | 2005 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/166242019-04-12T09:36:30Z Computational and experimental study of instrumented indentation Chollacoop, Nuwong, 1977- Subra Suresh. Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Massachusetts Institute of Technology. Dept. of Materials Science and Engineering. Materials Science and Engineering. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2004. Includes bibliographical references (p. 167-175). This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. The effect of characteristic length scales, through dimensional and microstructural miniaturizations, on mechanical properties is systematically investigated by recourse to instrumented micro- and/or nanoindentation. This technique is capable of extracting mechanical properties accurately down to nanometers, via rigorous interpretation of indentation response. Such interpretation requires fundamental understandings of contact mechanics and underlying deformation mechanisms. Analytical, computational and experimental approaches are utilized to elucidate specifically how empirical constitutive relation can be estimated from the complex multiaxial stress state induced by indentation. Analytical formulations form a framework for parametric finite element analysis. The algorithms are established to predict indentation response from a constitutive relation (hereafter referred to as "forward algorithms") and to extract mechanical properties from indentation curve (hereafter referred to as "reverse algorithms"). Experimental verifications and comprehensive sensitivity analysis are conducted. Similar approaches are undertaken to extend the forward/reverse algorithms to indentations using two ore more tip geometries. Microstructural miniaturization leads to novel class of materials with a grain size smaller than 100 nm, hereafter referred to as "nanocrystalline" material. Its mechanical properties are observed to deviate greatly from the microcrystalline counterparts. (cont.) In this thesis, experimental, analytical and computational approaches are utilized to elucidate the rate and size dependent mechanical properties observed in nanocrystalline materials. Indentations, as well as micro-tensile tests, are employed to attain various controllable deformation rates. A simple analytical model, hereafter referred to as Grain-Boundary-Affected-Zone (GBAZ) model, is proposed to rationalize possible rate-sensitivity mechanism. Systematic finite element analysis integrating GBAZ model is conducted with calibration against the experiments. The same GBAZ model, further utilized in the parametric finite element study, is capable of predicting the inverse Hall-Petch-type phenomenon (weakening with decreasing grain size) at the range consistent with the literature. by Nuwong Chollacoop. Ph.D. 2005-05-17T14:42:41Z 2005-05-17T14:42:41Z 2004 2004 Thesis http://hdl.handle.net/1721.1/16624 55858576 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 175 p. 4637595 bytes 6053084 bytes application/pdf application/pdf application/pdf Massachusetts Institute of Technology |
| spellingShingle | Materials Science and Engineering. Chollacoop, Nuwong, 1977- Computational and experimental study of instrumented indentation |
| title | Computational and experimental study of instrumented indentation |
| title_full | Computational and experimental study of instrumented indentation |
| title_fullStr | Computational and experimental study of instrumented indentation |
| title_full_unstemmed | Computational and experimental study of instrumented indentation |
| title_short | Computational and experimental study of instrumented indentation |
| title_sort | computational and experimental study of instrumented indentation |
| topic | Materials Science and Engineering. |
| url | http://hdl.handle.net/1721.1/16624 |
| work_keys_str_mv | AT chollacoopnuwong1977 computationalandexperimentalstudyofinstrumentedindentation |