Degree Type

Dissertation

Date of Award

1986

Degree Name

Doctor of Philosophy

Department

Materials Science and Engineering

Abstract

A mathematical analysis of the stress field of dislocations in a slip plane was applied to explain the optical birefringence in sodium chloride during plastic deformation. This high birefringence of slip planes accompanying plastic deformation, without appreciable isoclinic or isochromatic birefringence, makes it possible to study the plastic zone at the crack tip and the mechanisms of fracture. Three-point bending at a slow test speed was used to calculate the work of fracture (W(,wof)), the crack driving force (G), the crack propagation resistance (R), and the plastic energy dissipation rate ((phi)(,p)). The work of fracture and first maximum load are suggested as parameters suitable to indicate the occurrence of brittle to ductile transition.

DOI

https://doi.org/10.31274/rtd-180813-6892

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Bai-Yun Huang

Language

en

Proquest ID

AAI8703714

File Format

application/pdf

File Size

110 pages

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