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This dissertation presents four analytical modelsfor predicting
local buckling of delaminated composite plates,sandwichplates,
beam-plates with repairment fasteners, and laminated plates
withrepairment fasteners using continuous analysis.The
continuous analysis procedure can handle without difficulty
composite plates havingsingle and multiple through-the-width or
embedded delaminations of variousshapes and sizes at
anylocations.The method treats the discontinuous structure as a
body withoutdelamination but with a fictitious force system
added at a number of discrete points in thedelaminated region so
as to make the net interfacial tractions to vanish atthese
points. Hence, the procedure solves problems of delaminated
structuresdirectly as a continuous system.Results of the model
using such acontinuous analysis method should converge to
results of the original structurewhen the number of discrete
points taken in the delaminated region increases toa
sufficiently large number.A number of numerical
resultsaccounting for the effects of transverse normal
stiffnessesof the resin in the bond layer on the buckling load
of composite plates having delaminations of various shapes,
sizes, and at differentlocations are presented.A number of
numerical resultsaccounting for the effects of transverse normal
and shear stiffnessesof the core on the buckling load of
sandwich plates having delaminations of various shapes, sizes,
and at differentlocations are obtained.The illustrative examples
indicate that the present method is accurate and effective which
should be useful for practical applications.Based on the
continuous analysis mentioned above, a simple and
efficienttechnique for predicting the buckling load of the
delaminated plates repairedby fasteners is presented in this
dissertation.The effect of a fastener on the local
bucklingbehavior of the delaminated plates is modeled as axially
loaded elastic members which provide transversely inward
concentrated restraining forces on the upper and lowerparts of
the delaminated platesat the fastener positions.The method
presented in the study is straightforward,simple and accurate
for determining the buckling load of delaminated plates
withrepairing fasteners. For illustrative purposes, some
numerical examples accountingfor the effect of number and
locations offastener on the local buckling of delaminated
double-plates are presented.
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