Ductile fracture modeling : theory, experimental investigation and numerical verification

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.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Xue, Liang, 1973-

Advisor dc:contributor.advisor

• Tomasz Wierzbicki.

• Mechanical Engineering.

Statement dc:rights

• 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.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40876

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40876