Dissertation/Thesis Abstract

Investigation on the Effect of Void Orientation and Matrix Anisotropy Using a Modified Gurson Model
by Sagsoy, Baris, M.S., Southern Illinois University at Edwardsville, 2014, 67; 1571928
Abstract (Summary)

Estimation of ductile fracture plays a critical role in the analysis of material behavior. The Gurson model is a well-known micromechanical model for ductile fracture. This model can predict void growth. The drawback of using the Gurson model arises from the fact that it has no intrinsic ability to predict void coalescence. It has been known that the evolution of matrix orthotropy has not been taken into consideration during ductile fracture of anisotropic matrices. Therefore, a modified Gurson model proposed by Kweon is utilized to investigate ductile fracture of isotropic and anisotropic materials, while introducing an initial void shape. To validate the developed code for the modified Gurson model by Kweon, both the modified Gurson model and the original Gurson model are employed to simulate biaxial loading of a cube, which shows an identical match. After the validation of the code, the effect of spheroidal void are investigated using a tensile bar specimen made out of an isotropic matrix in three different geometries. Anisotropic matrices were introduced for further analysis of spheroidal voids. The approach taken involves the use of the ABAQUS software with a UMAT code that contains the modified Gurdon model, which was developed by Kweon. Simulation results indicate that the code accurately reproduces the Gurson model response. Using smooth and notch cylindrical bars with a homogenous matrix, the effect of the void aspect ratio with an initial porosity on ductile fracture are investigated. The initial porosity and initial void shape have a significant effect on ductile fracture of metals.

Indexing (document details)
Advisor: Kweon, Soondo
Commitee: Wang, Fengxia, Yan, Terry
School: Southern Illinois University at Edwardsville
Department: Mechanical and Industrial Engineering
School Location: United States -- Illinois
Source: MAI 54/02M(E), Masters Abstracts International
Subjects: Mechanical engineering
Keywords: Ductile fractures, Isotropic matrix, Isotropic voids, Material behavior
Publication Number: 1571928
ISBN: 978-1-321-45224-2
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