Degree Type

Dissertation

Date of Award

2020

Degree Name

Master of Science

Department

Materials Science and Engineering

Major

Materials Science and Engineering

First Advisor

Richard A LeSar

Abstract

Focusing on cavity nucleation, continuum damage mechanics models rely on a posteriori calibration of initial site density and loading conditions. However, empirically calibrated parameters are unreliable due to accelerated testing conditions and cannot be transferred to novel materials. To provide a more accurate description of the relationship between temperature, stress, microstructure, and the kinetics of void nucleation, we develop a physically-based nucleation model by coupling discrete dislocation dynamics (DDD) and cluster dynamics (CD) models. First, a continuum statistical approach developed for this study is shown, demonstrating the ability to model vacancies cluster size evolution as a function of time. Second, the implementation of the DDD method in the study of local energetics within a microstructure is presented. DDD has the capability to accurately model complex dislocation networks permitting a high-fidelity account of the local energy landscape arising from defect-defect interactions. Lastly, multiple potential nucleation sites in bulk are examined for nucleation. Our results are consistent with experimental observations indicating that nucleation is highly improbable in bulk.

DOI

https://doi.org/10.31274/etd-20210114-61

Copyright Owner

Millicent Atieno-Orondo Hoback

Language

en

File Format

application/pdf

File Size

44 pages

Media2.avi (6035 kB)

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