2026-09-19T16:00:03Zhttps://dspace.mit.edu/server/oai/requestoai:dspace.mit.edu:1721.1/331622022-01-13T07:54:36Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023
Lallit Anand.
Ames, Nicoli M. (Nicoli Margret), 1978-
Massachusetts Institute of Technology. Dept. of Mechanical Engineering.
Massachusetts Institute of Technology. Department of Mechanical Engineering
2006-06-20T12:52:16Z
2006-06-20T12:52:16Z
2003
2003
http://hdl.handle.net/1721.1/33162
54631106
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (leaves 91-92).
A significant advance in modeling the plastic deformation of amorphous polymers has been made by Parks, Argon, Boyce, Arruda, and their co-workers (e.g. Parks, Argon, & Bagepalli, 1985; Boyce, Parks, & Argon, 1998; Arruda & Boyce, 1993), and by Wu and Van der Giessen (1993). Although these models phenomenologically capture the large deformation elastic-viscoplastic response of these materials in a reasonably accurate manner, they do not adequately account for the creep response of these materials at stress levels below those causing "macro-yield", as well as the Bauschinger-type reverse yielding phenomena at strain levels less than ~ 30% associated with the macro-yield transient. Anand (2003) has recently generalized the model of Anand and Gurtin (2003) to begin to capture these important aspects of these material's mechanical response. In this work, we summarize Anand's three-dimensional theory and then specialize the constitutive equations to an approximate one-dimensional form. Also, we describe our monotonic, cyclic and creep experiments on the amorphous polymeric solid poly(methyl methacrylate) (PMMA), at ambient temperature and stress states under which this material does not exhibit crazing, and we outline detailed procedures for material parameter determination from these experiments. We have implemented the three-dimensional constitutive equations in the finite-element computer program ABAQUS/Explicit (ABAQUS, Inc., 2002), and using this finite-element program, we show numerical results to some representative problems in microindentation, and compare them against corresponding results from physical experiments.
by Nicoli Margret Ames.
S.M.
92 leaves
6267944 bytes
6273494 bytes
application/pdf
application/pdf
eng
Massachusetts Institute of Technology
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
Mechanical Engineering.
An internal variable theory for isotropic visco-elastic-plastic solids : application to indentation of amorphous polymeric solids
Thesis
application/pdf
false
Publication
unknown
unknown
<Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="1c8f859f-875a-496b-af8f-0152f99830c1">
<Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type>
<Language>eng</Language>
<Title>An internal variable theory for isotropic visco-elastic-plastic solids : application to indentation of amorphous polymeric solids</Title>
<PublishedIn>
<Publication>
</Publication>
</PublishedIn>
<PublicationDate>2003</PublicationDate>
<Authors>
<Author>
<DisplayName>Ames, Nicoli M. (Nicoli Margret), 1978-</DisplayName>
<Affiliation>
<OrgUnit>
</OrgUnit>
</Affiliation>
</Author>
</Authors>
<Editors>
</Editors>
<Publishers>
<Publisher>
<DisplayName>Massachusetts Institute of Technology</DisplayName>
<OrgUnit />
</Publisher>
</Publishers>
<License>http://dspace.mit.edu/handle/1721.1/7582</License>
<Keyword>Mechanical Engineering.</Keyword>
<Abstract>A significant advance in modeling the plastic deformation of amorphous polymers has been made by Parks, Argon, Boyce, Arruda, and their co-workers (e.g. Parks, Argon, & Bagepalli, 1985; Boyce, Parks, & Argon, 1998; Arruda & Boyce, 1993), and by Wu and Van der Giessen (1993). Although these models phenomenologically capture the large deformation elastic-viscoplastic response of these materials in a reasonably accurate manner, they do not adequately account for the creep response of these materials at stress levels below those causing "macro-yield", as well as the Bauschinger-type reverse yielding phenomena at strain levels less than ~ 30% associated with the macro-yield transient. Anand (2003) has recently generalized the model of Anand and Gurtin (2003) to begin to capture these important aspects of these material's mechanical response. In this work, we summarize Anand's three-dimensional theory and then specialize the constitutive equations to an approximate one-dimensional form. Also, we describe our monotonic, cyclic and creep experiments on the amorphous polymeric solid poly(methyl methacrylate) (PMMA), at ambient temperature and stress states under which this material does not exhibit crazing, and we outline detailed procedures for material parameter determination from these experiments. We have implemented the three-dimensional constitutive equations in the finite-element computer program ABAQUS/Explicit (ABAQUS, Inc., 2002), and using this finite-element program, we show numerical results to some representative problems in microindentation, and compare them against corresponding results from physical experiments.</Abstract>
<Access xmlns="http://purl.org/coar/access_right"
>
</Access>
</Publication>