dc.contributor.advisor |
Dr. Damian Horrigan |
en |
dc.contributor.advisor |
Assoc. Prof. Gordon Mallinson |
en |
dc.contributor.advisor |
Dr. Krishnan Jayaraman |
en |
dc.contributor.author |
Southward, Temoana |
en |
dc.date.accessioned |
2007-01-18T22:26:52Z |
en |
dc.date.available |
2007-01-18T22:26:52Z |
en |
dc.date.issued |
2005 |
en |
dc.identifier.citation |
Thesis (PhD--Engineering)--University of Auckland, 2005. |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/313 |
en |
dc.description.abstract |
The response of honeycomb sandwich structure to disbond damage, in a compressive stress field,
has been assessed. Two types of disbond were considered; those extending through the full width of
a panel (through-width) and those enclosed within the panel boundaries (embedded). For each type
of disbond the failure process was established through four-point bend testing of 56 sandwich
specimens. For both types of disbond, failure was found to be governed by buckling-driven disbond
growth and, consequently, models of buckling and disbond growth were developed.
All of the models decoupled the face-sheets of the sandwich and treated the core as a spring
foundation having a stiffness determined from equilibrium of a two-dimensional orthotropic solid.
A linear Winkler beam model was used to predict buckling of a through-width disbond. The model
buckling loads agreed with specimen test results with an average difference of 1.7%. A non-linear
Winkler beam model was then developed to predict post-buckling behaviour and the initiation of
disbond growth, through a fracture mechanics analysis. A characteristic growth curve, defining the
work input required to initiate disbond growth, was developed and agreed with specimen test results
with an average difference of 3.3%. The model also verified that disbond growth occurs in discrete
increments approximately equal to the diameter of the honeycomb cells.
A linear Winkler plate model was used to predict buckling of an embedded disbond. The model
buckling loads agreed with specimen test results with an average difference of 3.7%. A non-linear
Winkler plate model was then developed to predict post-buckling behaviour of a sandwich panel
containing an embedded disbond. The model considered contact conditions and modelled disbond
growth by releasing fractured nodes during load incrementation. Disbond growth initiation loads
agreed with specimen test results with an average difference of 15.8%. Failure loads consistently
over-predicted specimen test results by an average of 13.9%. It was concluded that the growth
initiation loads should be used as a conservative estimate of failure.
The models developed may be used to assess the criticality of disbond damage in sandwich structure
having thin-gauge, composite face-sheets. |
en |
dc.format |
Scanned from print thesis |
en |
dc.language.iso |
en |
en |
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.relation.isreferencedby |
UoA1567794 |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.title |
Buckling and growth of disbonds in honeycomb sandwich structure |
en |
dc.type |
Thesis |
en |
thesis.degree.discipline |
Engineering |
en |
thesis.degree.grantor |
The University of Auckland |
en |
thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.rights.holder |
Copyright: The author |
en |
pubs.local.anzsrc |
09 - Engineering |
en |
pubs.org-id |
Faculty of Engineering |
en |
dc.identifier.wikidata |
Q112867491 |
|