A finite element model of grain boundary sliding for nanostructured metals
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.
| Yazar: | |
|---|---|
| Diğer Yazarlar: | |
| Materyal Türü: | Tez |
| Dil: | eng |
| Baskı/Yayın Bilgisi: |
Massachusetts Institute of Technology
2005
|
| Konular: | |
| Online Erişim: | http://hdl.handle.net/1721.1/17774 |
| _version_ | 1826211462014566400 |
|---|---|
| author | Jérusalem, Antoine, 1979- |
| author2 | Raúl Radovitzky. |
| author_facet | Raúl Radovitzky. Jérusalem, Antoine, 1979- |
| author_sort | Jérusalem, Antoine, 1979- |
| collection | MIT |
| description | Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. |
| first_indexed | 2024-09-23T15:06:15Z |
| format | Thesis |
| id | mit-1721.1/17774 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T15:06:15Z |
| publishDate | 2005 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/177742019-04-11T01:45:48Z A finite element model of grain boundary sliding for nanostructured metals Jérusalem, Antoine, 1979- Raúl Radovitzky. Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. Aeronautics and Astronautics. Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004. Includes bibliographical references (p. 69-76). Nanocrystalline metals, i.e., polycrystalline metals with grain sizes in the nanometer range, have elicited significant interest recently due to their potential for achieving higher material strength in combination with increased formability at lower temperatures and higher strain rates, among other potential performance improvements in the material properties. In addition, there is a growing body evidence of unique deformation mechanisms furnishing a qualitatively different mechanical behavior in materials structured at the nanometer scale. In particular, the expected increase of the yield strength with the refinement of the microstructure appears to level off at grain sizes of the order of 10 to 50 nm and reverts to a decrease of strength with further reduction of grain size. Experimental studies and atomistic simulations have provided evidence of this peculiar behavior. In this work, we propose a continuum model describing the competing deformation mechanisms believed to determine the effective response of nanocrystalline materials. A phenomenological model considering grain boundary sliding and accommodation as uncoupled plastic dissipative deformation mechanisms is formulated to describe the constitutive behavior of grain boundaries. Tensile test simulations using the proposed model reproduce the inverse trend in the grain-size dependency of the macroscopic yield stress predicted by atomistic simulations and experiments. Even more noteworthy is the finding that the numerically predicted grain-size dependency of the yield stress shows a linear relation to the inverse square root of the grain size, a phenomenon identified as the inverse Hall-Petch effect. The importance of this result is lastly enhanced by the prediction (cont.) from the model that the observed discrepancy between molecular dynamics and experimental results may be strongly related to the deformation rate. by Antoine Jérusalem. S.M. 2005-06-02T18:36:01Z 2005-06-02T18:36:01Z 2004 2004 Thesis http://hdl.handle.net/1721.1/17774 56528790 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 76 p. 3703626 bytes 3710170 bytes application/pdf application/pdf application/pdf Massachusetts Institute of Technology |
| spellingShingle | Aeronautics and Astronautics. Jérusalem, Antoine, 1979- A finite element model of grain boundary sliding for nanostructured metals |
| title | A finite element model of grain boundary sliding for nanostructured metals |
| title_full | A finite element model of grain boundary sliding for nanostructured metals |
| title_fullStr | A finite element model of grain boundary sliding for nanostructured metals |
| title_full_unstemmed | A finite element model of grain boundary sliding for nanostructured metals |
| title_short | A finite element model of grain boundary sliding for nanostructured metals |
| title_sort | finite element model of grain boundary sliding for nanostructured metals |
| topic | Aeronautics and Astronautics. |
| url | http://hdl.handle.net/1721.1/17774 |
| work_keys_str_mv | AT jerusalemantoine1979 afiniteelementmodelofgrainboundaryslidingfornanostructuredmetals AT jerusalemantoine1979 finiteelementmodelofgrainboundaryslidingfornanostructuredmetals |