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Because the composite sandwich structure is made of laminated
plates and lack of transverse reinforcement, it is susceptible
to damage under impact. Two of the most important damage
mechanisms are delamination and buckling of the core. The
strength and stiffness of the composite structure are always
reduced as resul- ts of two damage types. This would be
especically serious for the circumstance of the structure
subjected to compression. Thus, delamination may proporgate
due to local buckling.Composite sand- wich beams, with or
without face-core delamination, objected to compression is
studied in this thesis.The delamination on the core-face
interface is theoretically computed by employing a fin- ite
elemennt method which is based on the mindlin's plate theory
and von Karman's large deformation hyperthesis. The two face
plates are modeled as two mindlin plates which are connected by
the core material. Stress compoments parallel to the face
plates in the core are neglected. It is showed that the results
have good correlation between the theoretical work and test
results. The other important damage mechanism of impact is
buckling of the core. This factor will affect the composite
sandwish beam very much. Therefore, it is not sufficient to
analyze the delamination under impact only con- sidering the
delamination on the core-face interface.
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