Ductile fracture modeling : theory, experimental investigation and numerical verification

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.

Bibliographic Details
Main Author: Xue, Liang, 1973-
Other Authors: Tomasz Wierzbicki.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2009
Subjects:
Online Access:http://hdl.handle.net/1721.1/40876
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author Xue, Liang, 1973-
author2 Tomasz Wierzbicki.
author_facet Tomasz Wierzbicki.
Xue, Liang, 1973-
author_sort Xue, Liang, 1973-
collection MIT
description Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.
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spelling mit-1721.1/408762020-04-07T21:31:20Z Ductile fracture modeling : theory, experimental investigation and numerical verification Xue, Liang, 1973- Tomasz Wierzbicki. Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering Mechanical Engineering. Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007. Includes bibliographical references (p. 215-228). The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture initiation in uncracked ductile solids is sensitive to the hydrostatic pressure and is dependent on the Lode angle. The damage plasticity model is established on a "cylindrical decomposition" system accounting for the pressure dependence, Lode angle dependence and the non-linear damage rule. Two internal variables are adopted to quantify the evolution of material properties. One is the plastic strain and the other is so-called damage variable. The joint effects of pressure and Lode angle define a fracture envelope in the principal stress space. Plastic deformation induced damage is expressed by an integral of the damage rate measured at current loading and deformation status with respect to the fracture envelope. A non-linear damage rule is proposed to characterize the damage accumulation with respect to the plastic strain. Furthermore, a damage related weakening factor is adopted to describe the material deterioration. (cont.) Aluminum alloy 2024-T351 is selected and a series of experiments have been conducted to determine the necessary material parameters for the description of the mechanical and damage properties. The numerical integration procedure is presented. The proposed model is numerically implemented into an explicit code. Simulations were performed and the results show good agreement with the experimental data. Several representative load conditions are also modeled. These simulations illustrate realistic crack patterns. In addition to the damage plasticity model, the micro void shearing mechanism is also introduced into a Gurson-like material model. by Liang Xue. Ph.D. 2009-01-23T14:53:28Z 2009-01-23T14:53:28Z 2007 2007 Thesis http://hdl.handle.net/1721.1/40876 187984250 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 228 p. application/pdf Massachusetts Institute of Technology
spellingShingle Mechanical Engineering.
Xue, Liang, 1973-
Ductile fracture modeling : theory, experimental investigation and numerical verification
title Ductile fracture modeling : theory, experimental investigation and numerical verification
title_full Ductile fracture modeling : theory, experimental investigation and numerical verification
title_fullStr Ductile fracture modeling : theory, experimental investigation and numerical verification
title_full_unstemmed Ductile fracture modeling : theory, experimental investigation and numerical verification
title_short Ductile fracture modeling : theory, experimental investigation and numerical verification
title_sort ductile fracture modeling theory experimental investigation and numerical verification
topic Mechanical Engineering.
url http://hdl.handle.net/1721.1/40876
work_keys_str_mv AT xueliang1973 ductilefracturemodelingtheoryexperimentalinvestigationandnumericalverification