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Due to laminated structure , manufacturing defects or external
impact , composite materials often contain delaminations . The
buckling behavior of laminated plates with rectangle delamination
under uniaxial compressive loading is studied here . Finite
element methods are used to evaluate the buckling load , and to
find out the corresponding buckling modes . Materials considered
include short fiber composite materials and long fiber composite
materials. For short fiber composite materials , the delaminated
plate is modelled as a two dimensional problem by neglecting the
effect of width. Two parameters , the size and the position along
the thickness direction of the delaminated region , are varied
to assess their influence on the buckling behavior of the plates .
In order to overcome the singularity of the crack tip , the
singular element is used around the crack tip to catch precise
stress distribution . For the long fiber composite materials ,
is considered also the influence of angle-ply and cross-ply on
the buckling behavior . Three parameters , including the size of
the delaminated region , the position of the delaminated region
in the thickness direction ,and the orientation of the fiber
direction , are varied to evaluate the buckling load and the
corresponding buckling modes . Uniform mesh refinement around
the delaminated reigon edge is enforced to overcome the singul-
arity of the crack tip . Whatever short fiber composite materials
or long fiber composite materials , the results indicate that the
buckling loads decrease as the delamination size increases , and
the buckling modes change from a global type to a mixed type ,
then to a local type .If the position of the delamination is closer
to the plate surface , the plates more easily buckle . Besides ,
for the long fiber composite materials , the buckling loads
decrease as the orientation of the fiber direction increases ,
and the buckling modes do not change . The influence of plate
width on the buckling behavior is not evident .
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