Early-state damage detection, characterization, and evolution using high-resolution computed tomography

dc.contributor.advisor Joseph Gray
dc.contributor.advisor Thomas Rudolphi
dc.contributor.author Grandin, Robert
dc.contributor.department Aerospace Engineering
dc.date 2018-08-11T10:23:31.000
dc.date.accessioned 2020-06-30T02:53:31Z
dc.date.available 2020-06-30T02:53:31Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 2014
dc.date.embargo 2015-07-30
dc.date.issued 2014-01-01
dc.description.abstract <p>Safely using materials in high performance applications requires adequately understanding the mechanisms which control the nucleation and evolution of damage. Most of a material's operational life is spent in a state with noncritical damage, and, for example in metals only a small portion of its life falls within the classical Paris Law regime of crack growth. Developing proper structural health and prognosis models requires understanding the behavior of damage in these early stages within the material's life, and this early-stage</p> <p>damage occurs on length scales at which the material may be considered ``granular'' in the sense that the discrete regions which comprise the whole are large enough to require special consideration.</p> <p>Material performance depends upon the characteristics of the granules themselves as well as the interfaces between granules. As a result, properly studying early-stage damage in complex, granular materials requires a means to characterize changes in the granules and interfaces. The granular-scale can range from tenths of microns in ceramics, to single microns in fiber-reinforced composites, to tens of millimeters in concrete. The difficulty of direct-study is often overcome by exhaustive testing of macro-scale damage caused by gross material loads and abuse. Such testing, for example optical or electron microscopy, destructive and further, is costly when used to study the evolution of damage within a material and often limits the study to a few snapshots. New developments in high-resolution computed tomography (HRCT) provide the necessary spatial resolution to directly image the granule length-scale of many materials. Successful application of HRCT with fiber-reinforced composites, however, requires extending the HRCT performance beyond current limits. This dissertation will discuss improvements made in the field of CT reconstruction which enable resolutions to be pushed to the point of being able to image the fiber-scale damage structures and the application of this new capability to the study of</p> <p>early-stage damage.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/13980/
dc.identifier.articleid 4987
dc.identifier.contextkey 6199706
dc.identifier.doi https://doi.org/10.31274/etd-180810-3537
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/13980
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/28167
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/13980/Grandin_iastate_0097E_14394.pdf|||Fri Jan 14 20:05:14 UTC 2022
dc.subject.disciplines Engineering
dc.subject.disciplines Mechanics of Materials
dc.subject.keywords computed tomography
dc.subject.keywords damage characterization
dc.subject.keywords damage evolution
dc.subject.keywords fiber reinforced composites
dc.subject.keywords GPU computing
dc.subject.keywords high-resolution computed tomography
dc.title Early-state damage detection, characterization, and evolution using high-resolution computed tomography
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isAuthorOfPublication 0619cddc-8e05-4b46-8f4e-6e3f90dd2e2a
relation.isOrgUnitOfPublication 047b23ca-7bd7-4194-b084-c4181d33d95d
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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