Mechanical Engineering Faculty Research

Title

On Ductile Fracture Initiation Toughness: Effects of Void Volume Fraction, Void Shape and Void Distribution

Document Type

Article

Publication Date

9-2005

Abstract

This paper studies the effects of the initial relative void spacing, void pattern, void shape and void volume fraction on ductile fracture toughness using three-dimensional, small scale yielding models, where voids are assumed to pre-exist in the material and are explicitly modeled using refined finite elements. Results of this study can be used to explain the observed fracture toughness anisotropy in industrial alloys. Our analyses suggest that simplified models containing a single row of voids ahead of the crack tip is sufficient when the initial void volume fraction remains small. When the initial void volume fraction becomes large, these simplified models can predict the fracture initiation toughness (JIc) with adequate accuracy but cannot predict the correct JR curve because they over-predict the interaction among growing voids on the plane of crack propagation. Consequently, finite element models containing multiple rows of voids should be used when the material has large initial void volume fraction.

Publication Title

International Journal of Solids and Structures

Volume

42

Issue

18-19

First Page

5097

Last Page

5117